JP2016131471A - Driving device for stepping motor and driving method of stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device for a stepping motor capable of increasing torque in a high-speed region.SOLUTION: The driving device for a stepping motor includes: a magnetization pattern storage sections (34, 64); and magnetization pattern selection parts (35, 65). In the magnetization pattern storage sections (34, 64), a plurality of high-speed magnetization sequences (11 to 16) set by combining a magnetization pattern of two-phase magnetization and other magnetization patterns of multi-phase magnetization are stored. The magnetization pattern selection parts (35, 65) are so set in advance as to select the high-speed magnetization sequences (11 to 16) corresponding to an electric angle position when a rotation speed is in a high-speed region.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a driving apparatus and a driving method for stepping a stepping motor by switching the excitation phase of an HB type five-phase stepping motor in which five excitation coils are connected in a ring shape.

  In general, when driving a motor rotor of a five-phase stepping motor having five excitation coils, a command pulse is input from the outside to the stepping motor driving device, and the driving device counts the input command pulses. At the same time, control is performed to rotate the motor rotor by an angle proportional to the total number of command pulses by switching excitation to the excitation coil of the five-phase stepping motor in accordance with the count value.

  In addition, for example, in order to make the positioning resolution of the motor rotor of a five-phase stepping motor fine, half-step driving in which the basic step angle determined from the mechanical structure of the five-phase stepping motor is divided in half and driven, Micro-step driving is performed in which the corner is further divided into smaller angles.

  For example, Japanese Patent No. 5327666 (hereinafter referred to as Patent Document 1) discloses a driving device for a stepping motor that performs microstep driving by dividing the basic step angle of an N-phase stepping motor into m.

  The driving device of the stepping motor according to Patent Document 1 includes an m-dividing counter that counts and outputs the number of steps in a fine step (microstep) and a basic step counter that counts and outputs the number of steps in a basic step (full step). The electrical angle position management means having the excitation phase combination output means for outputting the excitation combination of the two excitation sets, and the excitation ratio of the two excitation sets in the excitation combination according to the value of the m-divided counter and the value of the basic step counter An excitation ratio determining means for determining the unit excitation period, a unit excitation cycle output means for outputting a unit excitation switching command every time a predetermined unit excitation period T is counted, and a combined excitation period TC composed of an integral multiple of the unit excitation period T A combination excitation cycle output means for outputting a combination excitation switching command each time the value is counted, and every time a combination excitation switching command is output, or a combination A unit using the excitation ratio storage means for storing a new excitation ratio each time the value of the basic step counter is updated in addition to the output of the excitation switching command, and the excitation ratio stored in the excitation ratio storage means. Excitation waveform output means that switches the excitation and outputs sequentially through the drive element each time an excitation switching command is output, and the two-phase excitation constituting the excitation group is the motor of all terminals in the excitation coil The excitation is connected to either the positive electrode or the negative electrode of the drive power supply.

  The stepping motor driving apparatus according to Patent Document 1 will be briefly described. In the driving apparatus of Patent Document 1, a plurality of excitation sequences corresponding to each full-step position and each micro-step position are set. In this case, each excitation sequence corresponding to the full step position is composed of one excitation set in which two two-phase excitation patterns are combined, and excitation of these two-phase excitation patterns is performed while being shifted with respect to time. Thus, the synthesized four-phase excitation is realized. Each excitation sequence corresponding to a microstep position is configured by combining two excitation groups having two two-phase excitation patterns at an excitation ratio corresponding to the microstep position.

  Furthermore, in the driving device of Patent Document 1, each time a command palace is input, the address corresponding to each step position is managed by counting up or counting down, and the excitation sequence corresponding to the address is selected and the excitation is selected. The excitation pattern of the sequence is switched at every unit excitation cycle T generated irrespective of the command palace, and the excitation coils are sequentially excited in a predetermined cycle (excitation cycle TC). At this time, each time the excitation cycle TC is repeated, the address of the managed step position is confirmed and the corresponding excitation sequence is selected (updated).

  Further, in Patent Document 1, not only the address of the step position is selected for each excitation cycle TC as described above, but an excitation sequence corresponding to the full step position is selected every time the address of the full step position is counted. (Update) Excitation using the two-phase excitation pattern is performed in a predetermined cycle (excitation period TC).

  According to such a driving device of Patent Document 1, when the stepping motor performs microstep driving in an ultra-low speed region, for example, the period for updating the excitation sequence is stabilized, and the microstep driving is stabilized with smooth rotation. Can be done.

  In addition, when microstep drive is performed in the low speed region where the rotation speed of the stepping motor is slightly increased or in the medium speed region where it is further increased, the excitation sequence corresponding to the microstep position is thinned out when the excitation sequence is updated. The microstep drive can be stably performed while performing appropriately according to the rotation speed. Further, for example, in a low speed region or a medium speed region, it is possible to smoothly switch from microstep driving to full step driving, and it is possible to stably maintain constant speed rotation during full step driving.

Japanese Patent No. 5327666

Since stepping motors have excellent controllability, they have been widely used in industrial devices in various fields such as precision mechanical devices and measuring devices.
On the other hand, with the recent technological development, stepping motors that can obtain the required torque even when the rotation speed is high, and stepping motors that can obtain a larger torque in the low rotation speed and super rotation low speed regions have been newly developed, Has been sold. Further, for example, by using a stepping motor having a larger rated current, it is possible to increase the torque and speed of the stepping motor.

  For this reason, in industrial equipment where the stepping motor is already assembled and operating, increasing the torque of the stepping motor and increasing the speed as described above can improve the efficiency and productivity of the industrial equipment. Can be achieved.

  In particular, conventional stepping motors often have sufficient torque in the low speed region and medium speed region, but in high speed regions where the motor rotation speed is high, the motor coil (excitation coil) increases as the angular velocity increases. As a result, the current becomes difficult to flow through the motor coil, and the current saturation state in which a predetermined current does not flow through the exciting coil at a certain rotational speed or higher. As described above, since sufficient torque cannot be obtained when the stepping motor is saturated with current, it is difficult to increase the speed of the apparatus without replacing the stepping motor.

  As described above, using a stepping motor with a larger rated current makes it easier to secure torque in the high speed region, but as the current increases, the heat generation of the stepping motor and the heat generation of its driving device (driver) also increase. For this reason, depending on the device, a stepping motor having a large rated current may not be used.

  In addition, a large number of stepping motors and a large number of drive devices and controllers (controllers) that drive the stepping motors are used in one industrial device. A stepping motor having 100 axes or more may be used.

  For this reason, in order to replace the stepping motor assembled in one device with a new type stepping motor or a stepping motor with a large rated current for increasing torque or speeding up, many stepping motors must be replaced at the same time. Dedicated drive devices and control devices must also be replaced. Furthermore, since it is necessary to review the design of the power supply and the wiring, a large amount of money is required.

  In addition, since many industrial devices that use stepping motors have received safety standard certification from a predetermined certification body, stepping motors and their driving devices, which are important parts of equipment parts, are There was also a problem that it could not be easily replaced. For this reason, it has been eagerly desired by users to increase the torque in the high speed region and increase the speed and productivity of the apparatus without replacing the stepping motor.

  The present invention has been made in view of the above-described conventional problems. The object of the present invention can be applied without renewing the stepping motor by rewriting the internal logic circuit. It is an object of the present invention to provide a stepping motor driving apparatus and a stepping motor driving method capable of increasing torque in a high speed region while securing torque in a high speed region.

  In order to achieve the above object, a stepping motor drive device provided by the present invention switches the excitation phase of an HB type five-phase stepping motor in which five excitation coils are connected in a ring shape by inputting a command pulse, A stepping motor drive device for step-driving the stepping motor, wherein the motor rotation management unit counts the command pulses and manages the electrical angle position and rotation speed of the stepping motor, and excitation having a plurality of excitation patterns An excitation pattern storage unit for storing a sequence, an excitation pattern selection unit for selecting the corresponding excitation sequence from the excitation pattern storage unit based on an electrical angle position and a rotation speed managed by the motor rotation management unit, and a plurality of switching The excitation sequence selected by the excitation pattern selection unit. In a stepping motor drive apparatus comprising a switching unit that switches the excitation phase of the stepping motor by controlling ON / OFF of each switching element according to the excitation pattern of the excitation pattern, the excitation pattern storage unit stores the excitation phase A plurality of high-speed excitation sequences set by combining two-phase excitation excitation patterns whose combined impedance is lower than that of four-phase excitation and other multi-phase excitation excitation patterns are stored. When the rotation speed managed by the motor rotation management section is a high speed region in which the rotation speed managed by the motor rotation management section is equal to or higher than a predetermined high speed determination speed higher than a current saturation rotation speed at which the current flowing through the stepping motor is saturated, Pre-set to select the high-speed excitation sequence corresponding to the position It is an most important characterized in that is.

  In particular, in the stepping motor driving device according to the present invention, the excitation pattern storage unit stores a plurality of medium-speed excitation sequences having only four-phase excitation excitation patterns, and the excitation pattern selection unit performs the rotation. The medium speed excitation sequence corresponding to the electrical angle position is selected when the speed is in a medium speed region that is equal to or higher than a predetermined medium speed determination speed lower than the current saturation rotation speed and less than the high speed determination speed. It is preferable to set in advance.

  In the stepping motor drive device according to the present invention, the high-speed excitation sequence is set by combining the excitation pattern of the two-phase excitation with the excitation pattern of the four-phase excitation and / or the excitation pattern of the three-phase excitation. It is preferable.

  Further, in the stepping motor drive device of the present invention, the excitation pattern storage unit stores a plurality of high-speed sequence groups having a plurality of high-speed excitation sequences corresponding to each rotation speed range of the high-speed region, and the excitation pattern The selection unit is preferably set in advance so as to select the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotation speed.

In this case, it is preferable that each high-speed excitation sequence of the high-speed sequence group is set such that the excitation length of the entire sequence is set shorter as the rotational speed range becomes higher.
The high-speed excitation sequence selected when the rotation speed is equal to or higher than a predetermined ultra-high determination speed faster than the high-speed determination speed is an excitation pattern that forms a torque vector corresponding to one full step position; It is preferable to have an excitation pattern that forms a torque vector corresponding to the next full step position and / or an excitation pattern that forms a torque vector corresponding to a half step position between both full step positions.

  Furthermore, the stepping motor drive device of the present invention has a current saturation determination unit that determines that the current flowing through the stepping motor is saturated and detects the current saturation rotation speed, and the excitation pattern storage unit includes the current saturation determination unit. A plurality of the high-speed sequence groups corresponding to the speed range of the current saturation rotation speed are stored in advance, and the excitation pattern selection unit 1 corresponds to the current saturation rotation speed detected from the plurality of high-speed sequence groups. It is preferable that the high-speed sequence group is selected in advance.

  Next, the stepping motor driving method provided by the present invention switches the excitation phase of an HB type five-phase stepping motor in which five excitation coils are connected in a ring shape by inputting a command pulse, and steps the stepping motor. A driving method of a stepping motor to be driven, which is set by combining a two-phase excitation excitation pattern in which the combined impedance of the excitation phases is lower than a four-phase excitation excitation pattern and other multi-phase excitation excitation patterns. A plurality of high-speed excitation sequences are stored in advance in the excitation pattern storage unit, and the rotation speed managed by the motor rotation management unit is faster than a current saturation rotation speed at which a current flowing through the stepping motor is saturated. The high-speed corresponding to the electrical angle position in a high-speed region that is equal to or higher than a predetermined high-speed determination speed It is an most important feature that it comprises selecting the excitation sequence.

  In particular, the stepping motor driving method according to the present invention stores a plurality of medium-speed excitation sequences having only four-phase excitation excitation patterns in the excitation pattern storage unit in advance, and the rotation speed is Selecting the medium speed excitation sequence corresponding to the electrical angle position in a medium speed region that is equal to or higher than a predetermined medium speed determination speed slower than the current saturation rotation speed and less than the high speed determination speed. It is preferable to include.

  In the stepping motor driving method according to the present invention, a high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotation speed range of the high-speed region is stored in the excitation pattern storage unit in advance. Preferably, the method includes selecting the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotation speed in the high-speed region.

  In this case, according to the driving method of the present invention, the plurality of high-speed sequence groups corresponding to the speed range of the current saturation rotation speed are stored in advance in the excitation pattern storage unit, and the current flowing through the stepping motor is saturated. And detecting the current saturation rotation speed, and selecting one high-speed sequence group corresponding to the detected current saturation rotation speed from a plurality of the high-speed sequence groups. Is preferred.

  A stepping motor drive device according to the present invention includes a motor rotation management unit that manages an electrical angle position (address) and a rotation speed of a stepping motor by counting command pulses, an excitation pattern storage unit that stores a plurality of excitation sequences, An excitation pattern selection unit that selects an excitation sequence from the excitation pattern storage unit, and a switching unit that switches the excitation phase of the stepping motor by controlling ON / OFF of a plurality of switching elements.

  In particular, the excitation pattern selection unit of the present invention selects the excitation sequence for medium speed having only the excitation pattern of four-phase excitation from the excitation pattern storage unit in the medium speed region, and the current is saturated in four-phase excitation. When the high-speed region is higher than the high-speed rotation speed that is higher than the current saturation rotation speed, the excitation pattern for high-speed excitation is mixed and combined with, for example, the excitation pattern for two-phase excitation and the excitation pattern for four-phase excitation. It is set in advance to select from the part.

  According to such a stepping motor drive device of the present invention, when the rotation speed of the stepping motor is in a low speed region, for example, a low speed excitation sequence for performing microstep driving as in the past or other low speed excitation sequences is used. By doing so, the stepping motor can be smoothly rotated and an appropriate torque can be stably secured.

  Further, when the rotational speed is in the middle speed range, full-step driving is performed using an excitation pattern of four-phase excitation that simultaneously excites four excitation coils. As a result, the stepping motor can be rotated more smoothly in the medium speed region, and the combined torque by the four-phase excitation can be ensured appropriately.

  Further, when the rotational speed is in a high speed region, full-step driving is performed according to a high-speed excitation sequence having at least one excitation pattern for two-phase excitation. For example, when the excitation pattern of a 5-phase stepping motor is selected by selecting an excitation pattern of 2-phase excitation, for example, a predetermined current set is larger than when excitation is performed with an excitation pattern of 4-phase excitation such as a medium speed region. Although the combined torque when properly flowing is reduced, the combined impedance of the entire excited coil can be reduced (ie, the combined impedance when two of the five exciting coils are excited is This is lower than the combined impedance when four of the five exciting coils are excited).

  For this reason, the rotational speed of the motor is increased and the impedance of the exciting coil is increased, so that in the high speed region where the current is saturated in the four-phase excitation (current saturation rotational speed), the combined impedance is low. By using the excitation pattern, the current can flow more easily through the stepping motor than the four-phase excitation pattern in which the current is saturated. As a result, a larger combined torque can be obtained in the high-speed region.

  Therefore, a high-speed excitation sequence is set by mixing such an excitation pattern of two-phase excitation with, for example, an excitation pattern of four-phase excitation, and stepping is performed by selecting the high-speed excitation sequence in the high-speed area. Since the rate of torque reduction in the high speed region can be made smaller than before without increasing the rated current of the motor or increasing heat generation, the torque in the high speed region can be effectively increased.

  In addition, the drive device of the present invention can be applied to a conventional stepping motor by rewriting an internal logic circuit (program) in the conventional drive device, and thus has already been assembled in various devices. There is no need to replace the existing stepping motor. For this reason, the torque increase in the high-speed region as described above of the stepping motor and the speed increase due to the torque increase can be realized without causing a large cost burden.

  In such a drive device of the present invention, the high-speed excitation sequence is set by combining a two-phase excitation pattern and a four-phase excitation pattern and / or a three-phase excitation pattern. In this way, for example, considering the rotation characteristics and vibration characteristics of the stepping motor, by appropriately combining the excitation pattern of two-phase excitation, the excitation pattern of four-phase excitation and / or the excitation pattern of three-phase excitation, It is possible to perform high-speed rotation while suppressing the vibration of the stepping motor, and to effectively prevent the step-out phenomenon.

  In the stepping motor driving apparatus of the present invention, the excitation pattern storage unit stores a high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotation speed range of the high-speed region. The high-speed excitation sequence corresponding to the high-speed sequence group is selected based on the rotation speed.

  As a result, the stepping motor can be driven stepwise by selecting the high-speed excitation sequence that appropriately corresponds to the rotation speed in each rotation speed range of the high-speed region, so the stepping motor can be smoothly increased to a higher rotation speed. While being able to rotate, a step-out phenomenon can be prevented more effectively.

  In this case, in each high-speed excitation sequence of the high-speed sequence group, the excitation length of the entire sequence is set shorter as the rotational speed range becomes higher. As a result, even when the rotational speed is increased, when the high-speed excitation sequence is updated according to the input of the command pulse, the number of excitation patterns thinned out in the high-speed excitation sequence is reduced, and the high-speed excitation sequence is followed. The step driving can be performed stably and easily.

  Further, in the present invention, the high-speed excitation sequence selected when the rotation speed is equal to or higher than a predetermined ultra-high determination speed faster than the high-speed determination speed is an excitation pattern that forms a torque vector corresponding to one full step position, An excitation pattern for forming a torque vector corresponding to the next full step position and / or an excitation pattern for forming a torque vector corresponding to a half step position between the two full step positions. This makes it easy to rotate the motor to the next full-step position when performing full-step drive in the high-speed region, and effectively prevents the motor from following the switching of excitation by inputting a command pulse. Can be prevented.

  Furthermore, the drive device of the present invention has a current saturation determination unit that determines that the current flowing through the stepping motor is saturated and detects a current saturation rotation speed, and the excitation pattern storage unit includes a current saturation rotation speed. A plurality of high-speed sequence groups corresponding to the speed range are stored in advance, and the excitation pattern selection unit selects one high-speed sequence group corresponding to the detected current saturation rotation speed from the plurality of high-speed sequence groups. Is set in advance. As a result, the motor characteristics based on the inductance of the stepping motor can be determined based on the magnitude of the current saturation rotation speed, and the optimum high-speed sequence group suitable for the stepping motor can be selected, so that the stepping motor can be rotated more smoothly in the high-speed region. Can do.

  Next, in the stepping motor driving method according to the present invention, the medium speed excitation sequence having only the four-phase excitation pattern, the two-phase excitation pattern, and the other multi-phase excitation pattern are combined. A plurality of high-speed excitation sequences to be set are stored in advance in the excitation pattern storage unit. The medium speed excitation sequence is selected when the stepping motor is step-driven in the medium speed region, and the high speed excitation sequence is selected when the stepping motor is step driven in the high speed region.

  As a result, when the rotation speed of the stepping motor is in the low speed region, the stepping motor can be smoothly rotated and the appropriate torque can be stabilized by using, for example, a conventional low-speed excitation sequence that performs microstep driving. Can be secured. In addition, when the rotational speed is in the medium speed range, the stepping motor rotates smoothly by performing full-step driving using the excitation pattern of four-phase excitation that simultaneously excites four excitation coils, and synthesis by four-phase excitation is performed. Torque can be ensured appropriately.

  Further, when the rotational speed is in a high speed region, full-step driving is performed according to a high-speed excitation sequence having at least one two-phase excitation excitation pattern having a synthetic impedance lower than that of four-phase excitation and another multi-phase excitation excitation pattern. By doing so, it becomes easier for the current to flow through the stepping motor than the excitation pattern of the four-phase excitation in which the current is saturated, and as a result, a larger combined torque can be obtained. Therefore, the reduction rate of the torque of the stepping motor in the high speed region can be made smaller than before, and the torque in the high speed region can be effectively increased.

  In such a driving method of the present invention, a high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotation speed range in the high-speed region is stored in advance in the excitation pattern storage unit, and the rotation speed is high. In the area, one high-speed excitation sequence corresponding to the rotation speed is selected from the high-speed sequence group.

  As a result, in each rotation speed range of the high-speed region, the stepping motor can be step-driven by selecting a high-speed excitation sequence appropriately corresponding to each rotation speed range. While being able to rotate smoothly at high speed, a step-out phenomenon can be prevented more effectively.

  In this case, a plurality of high-speed sequence groups corresponding to the speed range of the current saturation rotation speed are stored in advance in the excitation pattern storage unit, and it is determined that the current flowing through the stepping motor is saturated and the current saturation rotation speed is determined. Based on the detected current saturation rotation speed, one corresponding high-speed sequence group is selected from a plurality of high-speed sequence groups. As a result, the motor characteristics based on the inductance of the stepping motor can be determined based on the magnitude of the current saturation rotation speed, and the optimum high-speed sequence group suitable for the stepping motor can be selected, so that the stepping motor can be rotated more smoothly in the high-speed region. Can do.

It is a block diagram which shows the internal structure of the drive device for stepping motors concerning the 1st Embodiment of this invention. (A) is a figure which defines the exciting coil of a 5-phase stepping motor and the direction of the exciting current which flows into each exciting coil, (b) is the torque which each exciting coil produces | generates when an exciting current flows. It is a figure which defines the relationship of a vector. It is a schematic diagram showing an example of an excitation pattern of an excitation sequence for performing step driving in a low speed region and a medium speed region when a command pulse CWP is input (CW direction). It is a schematic diagram which shows the example of the excitation pattern of the excitation sequence which performs step drive in the high-speed area | region at the time of command pulse CWP input (CW direction). It is a schematic diagram which shows the example of the excitation pattern of the excitation sequence which performs step drive in the low speed area | region and medium speed area | region at the time of command pulse CCWP input (CCW direction). It is a schematic diagram showing an example of an excitation pattern of an excitation sequence for performing step driving in a high speed region when a command pulse CCWP is input (CCW direction). It is a figure explaining the excitation pattern of the low speed excitation sequence in each step position from one full step position to the next full step position at the time of performing micro step drive. It is a figure explaining the unit excitation period in a low speed area | region, an excitation pattern, constant current control, and an excitation output. It is a schematic diagram explaining the electrode connection state of the exciting coil at the time of non-excitation. It is a figure explaining the unit excitation period in a medium speed area | region, an excitation pattern, constant current control, and an excitation output. It is a figure explaining a unit excitation cycle, an excitation pattern, constant current control, and an excitation output before an electric current saturates. It is a figure explaining a unit excitation period, an excitation pattern, constant current control, and an excitation output when an electric current is saturated. It is a figure explaining the relationship between a current saturation determination speed and the high-speed sequence group selected. It is a figure which shows the several high-speed excitation sequence which the high-speed sequence group for small inductance motors whose rated current is 1.4A / phase has. It is a figure which shows the several high-speed excitation sequence which the high-speed sequence group for middle inductance motors with a rated current of 1.4A / phase has. It is a figure which shows the several high-speed excitation sequence which the high-speed sequence group for small inductance motors with a rated current of 2.8A / phase has. It is a block diagram which shows the internal structure of the drive device for stepping motors concerning the 2nd Embodiment of this invention. Example 1 of comparing torque when the driving device (output stage chopper type) of the present invention according to the first embodiment and the conventional driving device are applied to a stepping motor having a rated current of 1.4 A / phase It is a graph. Torque when the driving device (output stage chopper type) of the present invention according to the first embodiment and the conventional driving device are applied to a stepping motor having a rated current of 1.4 A / phase different from that of the first embodiment. It is the graph of Example 2 compared. The driving device (output stage chopper type) of the present invention according to the first embodiment is applied to a stepping motor having a rated current of 2.8 A / phase, and torque when a current is output at a setting of 2.4 A / phase 12 is a graph of Example 3 in which a conventional driving device is applied to a stepping motor having the same rated current of 2.8 A / phase and a torque when a current is output at a setting of 2.8 A / phase is compared. Example 4 in which the torque when the drive device (motor drive voltage conversion type) of the present invention according to the second embodiment is applied to a stepping motor having a rated current of 1.4 A / phase is compared with the conventional drive device. It is a graph of.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
Here, FIG. 1 is a block diagram showing an internal configuration of the stepping motor driving apparatus according to the first embodiment. FIG. 2A is a diagram defining the excitation coil of the stepping motor and the direction of the excitation current, and FIG. 2B is a diagram defining the torque vector generated by each excitation coil when the excitation current flows. It is. 3 to 6 are schematic diagrams showing examples of excitation patterns in the angular velocity region in the CW or CCW direction.

  A driving device 10 for a stepping motor 1 according to the first embodiment shown in FIG. 1 is connected to an HB type five-phase stepping motor 1 of a Pedagon connection system. For example, a stepping motor 1 having a rated current of 1.4 A / phase is connected. This is a step-driven driver. The driving device 10 receives a command pulse CWP (ClockWise Pulse) or a command pulse CCWP (CounterClock Wise Pulse) from an external device such as a controller, and resolution (number of divisions of full step angle) when microstep driving is performed. A resolution command for determining is input.

  Here, the command pulse CWP is a command pulse for causing the motor rotor (rotor) of the five-phase stepping motor 1 to rotate forward clockwise to a predetermined rotation position. The command pulse CCWP is a command pulse for reversing counterclockwise to a predetermined rotation position.

Next, the excitation when the electrical angle round (7.2 °) of the five-phase stepping motor 1 is divided into 10 at the position of the full step (basic step) will be described with reference to FIGS.
First, as shown in FIG. 2 (a), the excitation coils of the five-phase stepping motor 1 adopting the Pentagon connection system are designated as 1a, 1b, 1c, 1d, 1e, and the respective excitation coils 1a, 1b, 1c, 1d, 1e. Are defined as A, a; B, b; C, c; D, d; E, e.

  In this case, the excitation currents A, B, C, D, and E and the excitation currents a, b, c, d, and e are opposite in the excitation coils 1a, 1b, 1c, 1d, and 1e with respect to the alphabets corresponding to each other. Current flowing in the direction is shown. Further, for example, when the excitation current A is passed through the excitation coil 1a, it is expressed as an excitation phase A, and when the excitation current a in the opposite direction is supplied is expressed as an excitation phase a. The same applies to the exciting coils 1b to 1e as in the exciting coil 1a.

  Further, as shown in FIG. 2 (b), the excitation currents A, a; B, b; C, c; D, d; E, the excitation coils 1a, 1b, 1c, 1d, 1e of the five-phase stepping motor 1 The torque vectors generated when e flows respectively are defined as torque vectors VA, Va, VB, Vb, VC, Vc, VD, Vd, VE, Ve, corresponding to the alphabets of the excitation currents. That is, the currents flowing through the exciting coil 1a are opposite to each other between the exciting current A and the exciting current a, and the torque vector VA and the torque vector Va are also opposite to each other.

  Next, the display of the excitation phase when the motor rotor (rotor) of the stepping motor 1 is positioned at each step position will be described. In order to simplify the expression, a combination of excitation phases when performing multi-phase excitation by simultaneously flowing an excitation current to a plurality of excitation coils of the five-phase excitation coils 1a to 1e. This is called an excitation pattern (excitation set).

  For example, simultaneous excitation of two phases of excitation phase A and excitation phase B is referred to as two-phase excitation, and this is referred to as excitation pattern AB. Further, simultaneous excitation of the four phases of excitation phase A, excitation phase B, excitation phase C, and excitation phase D is referred to as four-phase excitation, and this is referred to as excitation pattern ABCD. Furthermore, in order to realize the 4-phase excitation, the excitation pattern BC and the excitation pattern AD are sequentially shifted in time to realize the 4-phase excitation by combining the 2-phase excitation. It will be expressed as BC-AD.

  For example, in the present embodiment, as shown in FIG. 3, four-phase excitation is realized by performing four-phase excitation of the excitation pattern ABCD, or by combining by exciting the combination excitation pattern AB-CD. Four-phase excitation can be realized, whereby the motor rotor can be positioned at the full step position corresponding to the address “000”.

  When the command pulse CWP is input, the excitation phase is changed by switching the excitation pattern 10 times in the order of ABCD → BCDE → CDEa → DEab → Eabc → abcd → bcde → cdeA → deAB → eABC. The motor rotor can be driven stepwise (incremented) 10 times by 0.72 ° at the full step position to rotate (forward) 7.2 °, which makes one electrical angle.

  Further, by repeating the step of 10 full-step positions 50 times, the motor rotor can be rotated once by 360 °, that is, by a mechanical angle. When the command pulse CCWP is input, the motor rotor can be reversed by changing the excitation phase in the reverse order.

  As described above, the drive device 10 of the present embodiment that drives the five-phase stepping motor 1 stepwise outputs an excitation pattern output unit 30 that outputs an excitation pattern for exciting the excitation coils 1a to 1e by the input of the command pulse CWP or CCWP. And a switching unit 40 as an output stage that has a plurality of switching elements (power elements) TR1 to TR10 and controls ON / OFF of each of the switching elements TR1 to TR10 according to the excitation pattern output from the excitation pattern output unit 30; And a motor current control unit 50 that performs constant current control of an output stage chopper type of the five-phase stepping motor 1.

  The excitation pattern output unit 30 of the present embodiment includes an electrical angle position management unit (address counter) 31 that counts input command pulses and manages addresses corresponding to electrical angle positions (step positions), command pulses CWP, A motor rotation speed management unit (speed measurement counter) 32 that manages the rotation speed of the stepping motor 1 by counting the CCWP, an excitation cycle counter unit 33 that manages a constant unit excitation cycle T, and an excitation that stores a plurality of excitation sequences A pattern storage unit (memory) 34, an excitation pattern selection unit 35 that selects an excitation sequence from the excitation pattern storage unit 34, and outputs an excitation pattern for each unit excitation period T according to the excitation sequence, and a PWM constant current control circuit 51 An excitation / de-excitation processing unit 36 for outputting an excitation signal or a non-excitation signal in accordance with a signal from Current flowing through the exciting coil and a determining current saturation judgment section 37 that it has saturated.

  In the present embodiment, the electrical angle position and the rotational speed of the stepping motor 1 are managed by separate processing units of the electrical angle position management unit 31 and the motor rotational speed management unit 32. Two managements may be managed by one motor rotation management unit. In addition, a portion that performs other processing may be formed by one processing unit or a plurality of processing units.

  The electrical angle position management unit 31 in the excitation pattern output unit 30 manages an address corresponding to the electrical angle position (step position), and the number of managed addresses is set according to the resolution of the microstep. For example, in the case of the present embodiment, the resolution is set to “1/40” that divides the full step angle (0.72 °) into 40. Therefore, the number of addresses to be managed is set to 400 from “000” to “399” (full step drive 10 times × microstep division number 40) as shown in FIG. In the driving apparatus 10 of this embodiment, the user can arbitrarily set the resolution of the microstep within a predetermined range, and the address is managed based on the set resolution.

  The electrical angle position management unit 31 counts up the address value every time the command pulse CWP is input, counts down the address value every time the command pulse CCWP is input, and manages the value. The numerical value of the address is output to the motor rotation speed management unit 32 and the excitation pattern selection unit 35.

  If the electrical angle position management unit 31 can manage the electrical angle position of the stepping motor 1, for example, as described in Patent Document 1 described above, the number of steps in the basic step (full step) is described. It is also possible to form it by means having a basic step counter that counts the number of steps and a frequency division counter that counts the number of steps in the microstep.

  The motor rotational speed management unit 32 counts the command pulses CWP and CCWP, manages the rotational speed in calculation of the stepping motor 1 from the number of pulse inputs per unit time, and sets the managed rotational speed value as an excitation pattern. The data is output to the selection unit 35.

  The excitation cycle counter unit 33 manages a fixed unit excitation cycle T unrelated to the command pulses CWP and CCWP, and outputs an excitation switching command for each unit excitation cycle T. The unit excitation period T managed by the excitation period counter unit 33 is also output to the PWM constant current control circuit 51 in order to synchronize with the PWM timing in the constant current control described later.

  The excitation cycle counter unit 33 manages a sequence cycle ST that is an integral multiple of the unit excitation cycle T, and manages the excitation sequence with the electrical angle position management unit 31 each time the sequence cycle ST is counted. A sequence switching command for switching (or maintaining) according to the address value is output. For example, when the resolution is set to 1/40 and the unit excitation cycle T is set to 13.12 μs, an excitation switching command is output every 13.12, and 524 in the low speed region and the medium speed region. A sequence switching command is output every .8 μs (13.12 μs × 40).

  The excitation pattern storage unit 34 includes a low-speed excitation sequence as shown in FIGS. 7 and 8, a medium-speed excitation sequence as shown in FIGS. 10 to 12, and a plurality of high-speeds as shown in FIGS. A high-speed sequence group having an excitation sequence for use is stored.

  In this case, the low-speed excitation sequence includes the full step position and the microstep so that the stepping motor 1 is microstep driven in a low speed region where the rotational speed of the stepping motor 1 is less than a predetermined first rotational speed. This is an excitation sequence for positioning at each step position. Here, the first rotation speed in the present embodiment is, for example, 1.5 rps (90 rpm) as a predetermined rotation speed smaller than a current saturation rotation speed described later (in other words, a predetermined rotation speed before the current reaches saturation). The first rotation speed is a medium speed determination speed that becomes a boundary with the medium speed region in the stepping motor 1 having a rated current of 1.4 A / phase.

  For example, in the present embodiment (when the resolution is 1/40), the excitation pattern storage unit 34 is for 400 types of low speeds corresponding to addresses “000” to “399” in order to drive the stepping motor 1 by microsteps. An excitation sequence is set and stored.

  Each low-speed excitation sequence has a plurality of excitation patterns for positioning the motor rotor at the electrical angle position corresponding to each address. In particular, in the case of the present embodiment, each low-speed excitation sequence has an excitation pattern for 40 times that is switched every unit excitation cycle T by an excitation switching command output from the excitation cycle counter unit 33.

  In this case, the low-speed excitation sequence corresponding to the address of the full step position is formed by a combination of two two-phase excitation excitation patterns in order to realize four-phase excitation by synthesis.

  For example, as shown in FIGS. 3 and 7, the low-speed excitation sequence corresponding to the address “000” of the full step position is set by combining the excitation pattern BC for 20 times and the excitation pattern AD for 20 times ( That is, combination excitation pattern BC-AD).

  In this case, the direction of the torque vector (namely, VB + VC) by the excitation pattern BC is the same as the direction of the torque vector (namely, VA + VD) by the excitation pattern AD (see FIG. 2). Further, the magnitude of the torque vector synthesized by the excitation pattern BC is larger than the torque vector synthesized by the excitation pattern AD. The low-speed excitation sequence corresponding to the address “000” realizes the four-phase excitation ABCD by synthesis by alternately repeating these two excitation patterns BC and excitation pattern AD.

  Further, the low-speed excitation sequence corresponding to the address “040” of the next full step position is set by combining the excitation pattern CD for 20 times and the excitation pattern BE for 20 times, and these two two-phase excitation patterns CD. And the four-phase excitation BCDE by synthesis is realized by alternately repeating the two-phase excitation pattern BE. Similarly, the low-speed excitation sequence corresponding to each address of the full step position has two two-phase excitation patterns for realizing four-phase excitation by synthesis 20 times each.

  On the other hand, the low-speed excitation sequence corresponding to the address of the microstep position set between the addresses of the full step position includes the first combination excitation pattern obtained by combining two two-phase excitation patterns at one full step position, A second combined excitation pattern obtained by combining two two-phase excitation patterns at the next full step position is combined at a ratio corresponding to the step position.

  For example, as shown in FIGS. 3 and 7, the low-speed excitation sequences corresponding to the addresses “001” to “039” of the microstep positions set between the addresses “000” and “040” are as follows: First two-phase excitation pattern BC-AD combining two two-phase excitation patterns that realize four-phase excitation ABCD at the full step position and two two-phase excitations that realize four-phase excitation BCDE at the next full step position The second combination excitation pattern CD-BE obtained by combining the patterns is set in combination at a ratio corresponding to the step position.

  In this case, as the numerical value of the address increases, the number of first combination excitation patterns BC-AD is gradually decreased, and the number of second combination excitation patterns CD-BE is gradually increased, so that each microstep position is increased. Low speed excitation sequence is set.

  Similarly, after the address “041”, by combining the first combination excitation pattern and the second combination excitation pattern at a predetermined ratio, a low-speed excitation sequence corresponding to each address at the microstep position is set. Has been.

  Note that the low-speed excitation sequence in the present invention is not limited to the above-described microstep drive having a 1/40 resolution, but a microstep having a resolution greater than 1/40 or a smaller resolution. It may be set to perform driving, or may be set to perform full step driving or half step driving without performing microstep driving in a low speed region.

  Further, in the driving device 10 of the present embodiment, 1.5 rps (90 rpm) is set as described above as the first rotation speed (medium speed determination speed). The value of 60 rpm is also preliminarily set so that 1.5 rps and 1.0 rps can be switched by a switch. This setting of 1.0 rps is a preliminary setting when a motor having a very large inductance of 1.4 A / phase is used, and is normally set to 1.5 rps.

  Further, in the present invention, instead of setting a predetermined speed as the medium speed determination speed as described above, for example, an error between a sawtooth wave generated by a PWM constant current control circuit 51 as described later, a reference current, and a detected current It is possible to provide the excitation pattern output unit 30 with a medium speed determination unit that determines that the rotation speed of the stepping motor is in the medium speed region based on the comparison with the signal. Specific processing in the medium speed determination unit will be described later.

  In the excitation sequence for medium speed stored in the excitation pattern storage unit 34 of the present embodiment, the rotation speed of the stepping motor 1 is equal to or higher than the first rotation speed (medium speed determination speed) described above and less than the predetermined second rotation speed. This is an excitation sequence for positioning the stepping motor 1 so that it is driven not by microstep driving but by full step driving in a medium speed region. In this case, the second rotation speed is set to, for example, 5.65 rps (339 rpm), which is higher than a current saturation rotation speed described later, and the second rotation speed is a high speed determination speed that becomes a boundary with the high speed region.

  For example, as shown in FIG. 3 to FIG. 6 and FIG. 10 and the like, the excitation pattern storage unit 34 of the present embodiment stores ten types of medium speed excitation sequences. It has 40 excitation patterns with 40 unit excitation periods T.

  Each medium speed excitation sequence has only a four-phase excitation pattern that realizes a single four-phase excitation corresponding to each full step position by exciting the four phases simultaneously. For example, in the present embodiment, when the command pulse CWP is input (CW direction), the medium-speed excitation sequence corresponding to the addresses “000” to “039” positioned at one full step position is the excitation phase A and the excitation phase B. The four phases of excitation phase C and excitation phase D are excited at the same time. A torque vector of VA + VB + VC + VD is generated by exciting the four-phase excitation pattern ABCD.

  Further, when the command pulse CWP is input (CW direction), the excitation sequence for medium speed corresponding to the addresses “040” to “079” for positioning to the next full step position is excitation phase B, excitation phase C, excitation phase D. , And the four phases of excitation phase E are only 40 times four-phase excitation pattern BCDE that is excited simultaneously. Thereafter, similarly, the medium speed excitation sequence corresponding to a plurality (40) of addresses positioned at each full step position includes only a four-phase excitation pattern in which four phases are simultaneously excited in order to position at the full step position. Have a batch.

  On the other hand, when the command pulse CCWP is input (CCW direction), the numerical value of the address positioned at one full step position is different from that when the command pulse CWP is input (CCW direction). For example, as shown in FIG. In the medium speed excitation sequence corresponding to addresses “001” to “040” positioned at one full step position, four phases of excitation phase B, excitation phase C, excitation phase D, and excitation phase E are excited simultaneously. Only four four-phase excitation patterns BCDE are provided.

  Further, the excitation pattern storage unit 34 of the present embodiment stores a plurality of high-speed sequence groups corresponding to motor characteristics based on the inductance of the stepping motor 1 in advance. Each high-speed sequence group has a plurality of high-speed excitation sequences corresponding to a predetermined rotation speed range in a high-speed region where the rotation speed of the stepping motor 1 is equal to or higher than the second rotation speed described above.

  In particular, in the present embodiment, in the excitation pattern storage unit 34, as shown in FIG. 13, three types of high-speed sequence groups are preset for one rated current. For example, the rated current is 1.4A. For the / phase stepping motor 1, a large inductance type high speed sequence group, a medium inductance type high speed sequence group, and a small inductance type high speed sequence group are set.

  In this case, the high-inductance-type high-speed sequence group has a rotation speed (current saturation rotation speed: abbreviated saturation MRPS for short) when the current saturation determination unit 37 determines that the excitation current is saturated in the medium speed region, as will be described later. ) Is a high-speed sequence group selected by the excitation pattern selection unit 35 when it is smaller than a predetermined first set value (2 rps).

  The medium inductance type high-speed sequence group is selected by the excitation pattern selection unit 35 when the current saturation rotation speed is equal to or higher than the first set value (2 rps) and smaller than the predetermined second set value (3.5 rps). The small-inductance type high-speed sequence group is a high-speed sequence group selected by the excitation pattern selection unit 35 when the current saturation rotation speed is equal to or higher than the second set value (3.5 rps).

  Similarly, for a stepping motor 1 with a rated current of 2.4 A / phase and a stepping motor 1 with a 2.8 A / phase, a large inductance type high-speed sequence group, a medium inductance type high-speed sequence group, and Three types of high-speed sequence groups of small inductance type high-speed sequence groups are set. In this embodiment, three types of high-speed sequence groups are set for one rated current. However, in the present invention, two types of high-speed sequence groups are set for one rated current. Four or more types of high-speed sequence groups may be set.

  In addition, in the large, medium, and small inductance type high-speed sequence groups, a plurality of high-speed excitation sequences corresponding to the rotational speed range managed by the motor rotational speed management unit 32 are positioned at each full-step position. Is set according to the address to be used.

  For example, in a small inductance type high-speed sequence group with a rated current of 1.4 A / phase, a high-speed corresponding to addresses “000” to “039” positioned at one full step position when a command pulse CWP is input (CW direction). As the excitation sequences for use, six types of excitation sequences of the first high-speed excitation sequence 11 to the sixth high-speed excitation sequence 16 as shown in FIG. 14 are set.

  More specifically, the first high-speed excitation sequence 11 in the 1.4 A / phase small inductance type high-speed sequence group is an excitation sequence selected when the rotational speed is in the range of 5.65 rps to less than 6.00 rps. It is. The second high-speed excitation sequence 12 to the sixth high-speed excitation sequence 16 have a rotation speed in the range of 6.00 rps or more and less than 7.63 rps, in the range of 7.63 rps or more and less than 9.53 rps, or 9.53 rps or more, respectively. This is a high-speed excitation sequence selected in the range of less than 10.17 rps, the range of 10.17 rps or more and less than 10.90 rps, or the range of 10.90 rps or more. In this case, the rotation speed of 7.63 rps is defined as an ultra-high speed determination speed at which the rotation of the motor tends to be delayed with respect to the switching of excitation by the input of command pulses.

  Further, each of the high-speed excitation sequences 11 to 16 in the 1.4 A / phase small inductance type high-speed sequence group includes two-phase excitation excitation patterns (for example, two-phase excitation patterns BC) positioned at one full step position. These are set in combination with other multi-phase excitation patterns. In this case, the two-phase excitation pattern (two-phase excitation pattern BC) positioned at one full-step position is the first repetition number of each of the high-speed excitation sequences 11 to 16 (ie, “00” times) or from the beginning. The number of repetitions is set to several times (for example, “00” to “02”).

  In addition, as another multi-phase excitation pattern combined with such a two-phase excitation pattern (two-phase excitation pattern BC), as shown in FIG. 4, four phases are simultaneously excited and positioned at the full step position. Four-phase excitation pattern (for example, four-phase excitation pattern ABCD), three-phase excitation pattern (for example, three-phase excitation pattern BCD) to be positioned at a half-step position between full-step positions, and two-phase excitation pattern to be positioned at the next full-step position At least one excitation pattern (for example, a two-phase excitation pattern CD) and a four-phase excitation pattern (for example, a four-phase excitation pattern BCDE) for simultaneously exciting the four phases and positioning them at the next full step position is a stepping motor. 1 according to the rotation characteristics and rotation speed, and further how to use the stepping motor 1 .

  By combining these other multi-phase excitation patterns, it is possible to make the stepping motor 1 smoothly rotate by making it difficult for the stepping motor 1 to vibrate or step out as described later.

  Further, the number of repetitions of the excitation pattern set in each of the high-speed excitation sequences 11 to 16 (excitation length of the entire magnetic sequence) is the number of repetitions set in the above-described low-speed excitation sequence and medium-speed excitation sequence (40 In addition, the number of repetitions of the excitation pattern is reduced as the excitation sequence for high speeds in which the rotational speed range becomes higher.

  As a result, when the stepping motor 1 is step-driven in the high-speed region, the number of excitation patterns to be thinned out in the high-speed excitation sequence when the high-speed excitation sequence is switched (when the sequence is updated) by changing the full step position is set. Less.

  More specifically, in this embodiment, the excitation sequence is switched (updated) in order to drive the stepping motor 1 stepwise. The timing for switching the excitation sequence is the excitation pattern selection unit as will be described later. 35 is when the sequence switching command is received from the excitation cycle counter unit 33 and when the address managed by the electrical angle position management unit 31 is switched to the numerical value of the full step position.

  Particularly in the high-speed region, the address count-up or count-down due to the input of the command pulse CWP or CCWP is fast, so the interval at which the address is switched to the numerical value of the full step position is shorter than the interval at which the sequence switching command is received. For this reason, in the high-speed region, the excitation sequence is substantially switched at the timing when the address managed by the electrical angle position management unit 31 is switched to the numerical value of the full step position.

  In such a case, since the switching interval of the high-speed excitation sequence is shortened in the high-speed region, for example, the number of repetitions of the excitation pattern in the high-speed excitation sequence is 40 cycles (the high-speed excitation sequence has 40 excitation patterns). ), Before the excitation pattern is repeated 40 times, the high-speed excitation sequence is switched to the next full-step position high-speed excitation sequence, and the excitation pattern set to the number of times after the high-speed excitation sequence is It will be thinned out (the back side excitation pattern will not be output).

  On the other hand, as described above, the number of repetitions of the excitation pattern in each high-speed excitation sequence is less than 40 cycles, and the number of repetitions of the excitation pattern increases as the high-speed excitation sequence has a higher rotation speed range. By reducing the number, it is possible to reduce the number of excitation patterns to be thinned out in the high-speed excitation sequence, and to facilitate stable and stable full-step driving according to the high-speed excitation sequence.

  Here, when the first high speed excitation sequence 11 to the sixth high speed excitation sequence 16 in the 1.4 A / phase small inductance type high speed sequence group shown in FIG. The first high-speed excitation sequence 11 corresponding to the addresses “000” to “039” in the hour (CW direction) includes a two-phase excitation pattern BC set in a cycle of “00” to “02”, and “03 ”Times to“ 26 ”cycles, and a four-phase excitation pattern ABCD in which four phases are excited simultaneously, and the total number of repetitions is formed from 27 excitation patterns.

  As described later, the first high-speed excitation sequence 11 has the two-phase excitation pattern BC in which the combined impedance of the entire coil is lower than the four-phase excitation pattern ABCD. It is possible to make the current flow through the stepping motor 1 more easily than the excitation pattern of excitation. Accordingly, it is possible to effectively increase the torque in the high speed region where the rotation speed is 5.65 rps or more while suppressing the decrease rate of the combined torque accompanying the current saturation.

  Further, when the first high-speed excitation sequence 11 has not only the two-phase excitation pattern BC but also the four-phase excitation pattern ABCD on the subsequent stage side, for example, the high-speed excitation sequence is switched by changing the address of the full step position. When it is renewed, it can exhibit a relaxed action, hardly cause vibration of the stepping motor 1, and can effectively prevent the step-out phenomenon.

  Further, as shown in FIG. 14, the second high-speed excitation sequence 12 selected in the range where the rotation speed is 6.00 rps or more and less than 7.63 rps is set to the cycle of “00” to “02”. It has a two-phase excitation pattern BC and a four-phase excitation pattern ABCD that is set to a cycle of “03” to “20” times and four phases are excited simultaneously.

  That is, the second high-speed excitation sequence 12 is formed from 21 excitation patterns in total, and the number of excitation pattern repetitions is smaller than that of the first high-speed excitation sequence 11. Similar to the first high-speed excitation sequence 11, the second high-speed excitation sequence 12 is also effective in controlling the torque in a high-speed region where the rotational speed is 6.00 rps or more by suppressing the decrease rate of the combined torque accompanying current saturation. Can be extended.

  The third high-speed excitation sequence 13 selected in the range where the rotation speed is 7.63 rps (ultra high-speed determination speed) or more and less than 9.53 rps includes a two-phase excitation pattern BC set to “00” cycles and “ It is set to a cycle of “01” to “16” times, and is set to a four-phase excitation pattern ABCD in which four phases are excited simultaneously, and a cycle of “17” times to “19” times, and positioned at the next full step position. And a two-phase excitation pattern CD that is formed from excitation patterns for a total of 20 repetitions.

  As a result, it is possible to effectively increase the torque in the high speed region where the rotational speed is 7.63 rps or higher. Also, by having the two-phase excitation pattern CD that is positioned at the next full step position, the motor can be easily rotated to the next full step position in a high speed region that is higher than the ultra high speed determination speed (7.63 rps), and the command pulse It is possible to effectively prevent the rotation of the motor from following the switching of excitation by the input of.

  A fourth high-speed excitation sequence 14 selected in a range where the rotation speed is 9.53 rps or more and less than 10.17 rps, and a fifth high-speed excitation sequence selected in a range where the rotation speed is 10.17 rps or more and less than 10.90 rps. 15 has the two-phase excitation pattern BC, the four-phase excitation pattern ABCD, and the two-phase excitation pattern CD in the ratio shown in FIG. It is possible to effectively increase the torque of the motor, and it is possible to effectively prevent the rotation of the motor from following the switching of excitation by inputting a command pulse.

  The sixth high-speed excitation sequence 16 selected in the range where the rotational speed is 10.90 rps or more includes a two-phase excitation pattern BC set in a cycle of “00” to “02”, and “03” to “ The cycle is set to “04” times, and the 3-phase excitation pattern BCD is positioned at the half step position, and the cycle is set to “05” times to “13” times. The four phases are excited simultaneously to the next full step position. It has a four-phase excitation pattern BCDE for positioning, and the total number of repetitions is formed from 14 excitation patterns.

  The sixth high-speed excitation sequence 16 selected in such a high-speed region can effectively increase the torque in the high-speed region, and the rotation of the motor is not delayed with respect to the input of the command pulse. In addition, the motor can be further easily rotated to the next full step position.

  The excitation pattern selection unit 35 in the excitation pattern output unit 30 of the present embodiment includes a rotation speed managed by the motor rotation speed management unit 32 from a plurality of excitation sequences stored in the excitation pattern storage unit 34 described above. Based on the address (electrical angle position) managed by the electrical angle position management unit 31, one appropriate excitation sequence is selected, and according to the selected excitation sequence, the excitation pattern is sent to the switching unit 40 that is the output stage. Output every unit excitation cycle T.

  The excitation / non-excitation processing unit 36 in the excitation pattern output unit 30 of this embodiment switches the excitation state and the non-excitation state in accordance with a signal from the PWM constant current control circuit 51 of the motor current control unit 50, thereby exciting coils. Output stage chopper type current control is performed to control the current flowing through 1a to 1e to be constant.

Here, the output stage chopper type constant current control by the motor current control unit 50 and the excitation / non-excitation processing unit 36 will be described with reference to FIGS.
The motor current control unit 50 of the present embodiment includes a power source PS1 that supplies power for exciting the excitation coils 1a to 1e, a capacitor C1 that smoothes the voltage of the power source PS1, and an excitation coil 1a to perform constant current drive. A current detection resistor R1 that detects a current flowing through 1e, and a PWM constant current control circuit 51 that adjusts the time of excitation output to the excitation coils 1a to 1e according to the impedance of the excitation coils 1a to 1e. The output stage chopper type constant current control is configured in the same manner as a conventional general motor current control unit.

  Here, for example, as shown in FIG. 8, every time the excitation pattern selection unit 35 of the excitation pattern output unit 30 outputs an excitation switching command from the excitation cycle counter unit 33 (every unit excitation cycle T), for example, 2 Constant current control using an example of outputting an excitation pattern according to a predetermined excitation sequence such as phase excitation pattern BC, two-phase excitation pattern AD, two-phase excitation pattern BC, two-phase excitation pattern AD,. Will be described.

  At this time, the information of the unit excitation period T is also output to the PWM constant current control circuit 51 of the motor current control unit 50, and a sawtooth wave having a plurality of substantially triangular vibrations is generated for each unit excitation period T. At the same time, the PWM constant current control circuit 51 generates an error signal between the reference current value and the detection current generated at both ends of the current detection resistor R1 in FIG. And the above-mentioned sawtooth wave level. When the relationship of error signal ≧ sawtooth wave is established, the excitation / non-excitation processing unit 36 sets the excitation output to the excited state and allows a predetermined current to flow through the excitation coil (excitation coil is excited).

  When the relationship of error signal <sawtooth wave is established, a signal is output from the PWM constant current control circuit 51, and the excitation output is de-energized by the excitation / de-excitation processing unit 36. In particular, in this non-excited state, all the terminals are connected to the positive electrode as shown in FIGS. 9A and 9B so that the terminals of the exciting coils 1a to 1e do not enter a high impedance state ( Hereinafter, this state is referred to as “positive OFF”), or all terminals are connected to the negative electrode (hereinafter, this state is referred to as “negative OFF”). By performing such “positive OFF” and “negative OFF”, it becomes possible to reduce the overshoot of the current when switching the excitation output and improve the damping characteristic, thereby reducing vibration and noise. be able to.

  In this embodiment, when the excitation output is set to the non-excitation state by the excitation / de-excitation processing unit 36, “positive OFF” may be always selected in all non-excitation states, or “negative OFF” is always set. May be selected. Or, in the non-excitation state, “positive OFF” and “negative OFF” may be switched regularly (for example, alternately), or “positive OFF” and “negative OFF” may be switched randomly. good.

  By performing such output stage chopper type constant current control, as shown in FIG. 8, for example, when the current flowing through the current detection resistor R1 is likely to increase due to the low rotation speed, the level of the error signal is reduced. Since it descends, the excitation output time is shortened, and as a result, it is possible to perform control in which the current flowing through the excitation coils 1a to 1e is reduced.

  On the other hand, for example, when the current flowing through the current detection resistor R1 decreases due to an increase in the rotational speed (see, for example, FIG. 11), the error signal level increases, so that the excitation output time can be lengthened. Thereby, the control which increases the electric current which flows into the exciting coils 1a-1e can be performed. Thus, in the drive device 10 of the present embodiment, both the excitation output and the constant current control for each unit excitation cycle T can be performed simultaneously with a simple circuit configuration.

  For example, as shown in FIG. 12, the current saturation determination unit 37 determines whether or not there is a non-excitation state within one unit excitation cycle T, and sets the flag 1 when there is no non-excitation state. And a second determination unit that checks the state of the flag 1 and determines that the current has been saturated by setting the flag 2 if the state in which the flag 1 is set continues for three unit excitation periods T.

  For example, when the excitation coils 1a to 1e are excited with a four-phase excitation pattern in the medium speed region, the impedance of the excitation coil increases as the rotation speed of the stepping motor 1 increases. For this reason, when the rotation of the stepping motor 1 becomes faster than a certain rotational speed, the excitation pattern is switched before the current rises to a predetermined magnitude, and sufficient torque cannot be obtained. Thus, the state where the excitation pattern is switched before the current rises to a predetermined magnitude is a state where the current is saturated. Note that the rotation speed at which the current reaches saturation differs depending on the motor characteristics of the stepping motor.

  In the current saturation determination unit 37 of the present embodiment, whether or not the excitation pattern is switched before the current rises to a predetermined magnitude, in other words, the non-excitation state is set within one unit excitation cycle T in constant current control. The first determination unit determines whether or not there is any. In this case, in the first determination unit, when there is a non-excitation state within one unit excitation cycle T, the first determination unit maintains the state in which the flag 1 is turned down, and non-excitation within one unit excitation cycle T. When there is no excitation state, processing for setting flag 1 is performed. Further, for example, when it is determined that there is a non-excitation state within one unit excitation cycle T after the flag 1 is set, processing for depressing the flag 1 again is performed.

  Further, the second determination unit of the current saturation determination unit 37 determines whether the flag 1 is set or falls by the processing of the first determination unit, and maintains the state in which the flag 1 is set in three unit excitation cycles T. Is determined to be a point in time when a current saturation state is reached in which the current flowing through the stepping motor 1 is saturated and does not flow to a predetermined magnitude, and a process of setting the flag 2 is performed.

  At the same time, when the flag 2 is set, the current saturation determination unit 37 detects the rotation speed of the stepping motor 1 managed by the motor rotation speed management unit 32 at that time and stores it in the memory as the current saturation rotation speed. To do. The current saturation rotational speed detected by the current saturation determination unit 37 is one high-speed sequence group of three types of large, medium, and small inductance types stored in the excitation pattern storage unit 34 as described above. This is used when the sequence group is selected by the excitation pattern selection unit 35.

  As described above, instead of the predetermined speed being set in advance as the medium speed determination speed, for example, the excitation speed output unit 30 determines that the rotation speed of the stepping motor is in the medium speed region. (The illustration is omitted.) In this case, the medium-speed determination unit can determine the excitation duty ratio of the excitation output (that is, within the unit excitation cycle T expressed by “excitation output time / unit excitation cycle T”). The ratio of the excitation output time (ON time) is determined whether or not it exceeds 60%, and when it exceeds 60%, the medium speed first determination unit that sets the flag 1 and the state of the flag 1 are confirmed. A medium-speed second determination unit that sets the flag 2 when the state in which the flag 1 is set continues for three unit excitation periods T;

  In such a medium speed determination section, the medium speed first determination section measures the ON time and maintains the state in which the flag 1 is turned down when the excitation duty ratio does not exceed 60%. When the duty ratio exceeds 60%, processing for setting the flag 1 is performed. Further, for example, when it is determined that the excitation duty ratio has become 60% or less after the flag 1 is set, processing for depressing the flag 1 again is performed. Further, in the case where the medium speed second determination unit determines whether the flag 1 is set or falls by the processing of the first determination unit, and the state in which the flag 1 is set is maintained with three unit excitation cycles T. By determining that the rotation speed of the stepping motor is in the medium speed region and performing the process of setting the flag 2, it is possible to output a medium speed region signal to the excitation pattern selection unit 35.

  The switching unit (output stage) 40 according to the present embodiment includes switching elements (high-side power elements) TR1, TR3, and TR5 that control conduction or cutoff between the excitation coils 1a to 1e of each phase and the positive electrode of the motor current control unit 50. , TR7, TR9, switching elements (low-side power elements) TR2, TR4, TR6, TR8, TR10 for controlling conduction or blocking between the excitation coils 1a to 1e of each phase and the negative electrode of the motor current control unit 50, and excitation coils Diodes D1 to D10 that bypass electromotive force generated by 1a to 1e, a power element drive circuit 41 that switches ON / OFF of each switching element TR1 to TR10 according to the excitation pattern output from the excitation pattern output unit 30, and a stepping motor 1 and output terminals OUT1 to OUT5 connected to 1 General switching unit (output stage) have the same configuration.

Next, a method for step-driving the stepping motor 1 having a rated current of 1.4 A / phase using the above-described drive device 10 of the present embodiment will be described.
When the command pulse CWP or CCWP is input to the excitation pattern output unit 30, the electrical angle position management unit 31 counts up the address every time the command pulse CWP is input, and every time the command pulse CCWP is input. The address is counted down, the numerical value of the address is managed, and the numerical value of the address is output to the motor rotation speed management unit 32 and the excitation pattern selection unit 35. Further, the motor rotation speed management unit 32 manages the rotation speed of the stepping motor 1 from the number of pulse inputs per unit time, and outputs a numerical value of the managed rotation speed to the excitation pattern selection unit 35.

  In addition, the excitation cycle counter unit 33 of the excitation pattern output unit 30 manages a constant unit excitation cycle T that is unrelated to the command pulses CWP and CCWP, and outputs an excitation switching command for each unit excitation cycle T. And output to the PWM constant current control circuit 51. Furthermore, the excitation cycle counter unit 33 outputs a sequence switching command to the excitation pattern selection unit 35 every fixed sequence cycle ST (a cycle that is an integral multiple of the unit excitation cycle T).

  In the excitation pattern selection unit 35 of the excitation pattern output unit 30, the rotation speed output from the motor rotation speed management unit 32 and the electrical angle position management unit among the plurality of excitation sequences stored in the excitation pattern storage unit 34. Based on the numerical value of the address output from 31, an excitation sequence that meets the conditions is selected, and excitation patterns are sequentially output for each unit excitation period T according to the selected excitation sequence.

  At the same time, the excitation / non-excitation processing unit 36 of the excitation pattern output unit 30 performs constant current control by switching between the excitation state and the non-excitation state according to the signal from the PWM constant current control circuit 51 of the motor current control unit 50. .

  As a result, the switching unit 40 controls the ON and OFF of the switching elements TR1 to TR10 according to the excitation pattern output from the excitation pattern selection unit 35 and the signal from the excitation / non-excitation processing unit 36, thereby controlling the excitation coil. The stepping motor 1 can be step-driven by switching the excitation.

  Here, for example, in the case where the input of the command pulse is slow and the stepping motor 1 is rotated in a low speed region where the rotational speed is less than the first rotational speed (1.5 rps), refer to FIG. 3, FIG. 7, and FIG. While explaining. In particular, in the present embodiment, a case where microstep driving with a resolution of 1/40 is performed in the low speed region will be described, but the present invention does not perform microstep driving in the low speed region but performs full step driving or The present invention can also be applied when half-step driving is performed.

  In the low speed region, for example, when the address managed by the electrical angle position management unit 31 is “000”, the excitation pattern selection unit 35 selects the address from a plurality of low speed excitation sequences stored in the excitation pattern storage unit 34. The low-speed excitation sequence corresponding to “000”, that is, the low-speed excitation sequence (see FIG. 7) in which 20 excitation patterns BC and 20 excitation patterns AD are alternately combined is selected. According to the low-speed excitation sequence, the excitation pattern is switched in order for each unit excitation period T and output to the switching unit 40.

  Thus, in the exciting coils 1a to 1e, two sets of excitation pattern BC and excitation pattern AD are alternately repeated to generate a combined torque vector of four-phase excitation ABCD, and the motor rotor is set to the address “000”. It can be positioned at the full step position.

  When the excitation pattern output (output for each unit excitation cycle T) is performed 40 times according to the low-speed excitation sequence corresponding to the address “000”, the excitation pattern selection unit 35 performs the sequence from the excitation cycle counter unit 33. In response to the switching command, the numerical value of the address managed by the electrical angle position management unit 31 is read, and the low-speed excitation sequence corresponding to the address is selected.

  For example, when the sequence switching command is received after 40 times of the excitation pattern of the low-speed excitation sequence corresponding to the address “000” is received and the address of the electrical angle position management unit 31 is “000”, the address “000” is again displayed. The low speed excitation sequence corresponding to “000” is selected, and the excitation pattern of the low speed excitation sequence is performed 40 times.

  On the other hand, when the sequence switching command is received, if the address of the electrical angle position management unit 31 is counted up to “001” by the input of the command pulse CWP, the low-speed excitation sequence corresponding to the address “001” The excitation sequence is switched by selecting and the excitation pattern is output 40 times according to the low-speed excitation sequence corresponding to “001”.

  In this case, each of the low-speed excitation sequences corresponding to the addresses “001” to “039” is a first combination of two two-phase excitation patterns that realize four-phase excitation ABCD at the full step position as described above. The combination excitation pattern BC-AD and the second combination excitation pattern CD-BE obtained by combining two two-phase excitation patterns that realize the four-phase excitation BCDE at the next full step position are in proportion to the step position. They are set in combination (see FIGS. 3 and 7).

  Therefore, the excitation pattern according to the low-speed excitation sequence corresponding to the address “001” (that is, the low-speed excitation sequence in which 20 excitation patterns BC, 19 excitation patterns AD, and 1 excitation pattern BE are combined). Is output 40 times, the motor rotor can be positioned at the microstep position corresponding to the address “001” obtained by dividing the full step position by 40.

  Similarly, while performing excitation pattern output according to the low-speed excitation sequence 40 times, each time a sequence switching command is received, the low-speed excitation sequence corresponding to the address managed by the electrical angle position management unit 31 is selected. By updating (switching) the low-speed excitation sequence, the stepping motor 1 can be micro-step driven.

  In this embodiment, as described above, every time the excitation pattern of the low-speed excitation sequence is performed 40 times (every time the sequence switching command is received), not only the low-speed excitation sequence is updated, but also the command pulse CWP or command The low-speed excitation sequence is updated every time the address of the electrical angle position management unit 31 is switched to the address corresponding to the full step position by the input of the pulse CCWP.

  As a result, the stepping motor 1 can be stably micro-step driven in the low speed region, and an appropriate torque can be stably secured. Further, for example, even when the rotation speed of the stepping motor 1 is increased in the low speed region, the excitation sequence corresponding to the full step position address is prevented from being thinned out at the time of updating the excitation sequence, and the micro step position address is also reduced. The microstep drive can be smoothly performed by reducing the thinning of the excitation sequence corresponding to.

  Next, in the present embodiment, the rotation speed of the stepping motor 1 is increased, and stepping is performed in a medium speed region where the rotation speed is 1.5 rps (first rotation speed) or more and less than 5.65 rps (second rotation speed). When the motor 1 is rotated, the step driving of the stepping motor 1 is switched from micro step driving in the low speed region to full step driving.

  In this case, the excitation sequence is updated every time the sequence switching command is received as described above, and every time the address of the electrical angle position management unit 31 is switched to the address corresponding to the full step position. When the command pulse input speeds up and the cycle at which the full step position address is switched is shorter than the fixed cycle at which the sequence switching command is output, the excitation sequence is updated at the full step position. It is possible to match the timing when the address is switched.

  In such a low speed region, the excitation sequence is updated at the timing when the address of the full step position is switched, so that when switching from the micro step drive in the low speed region to the full step drive in the medium speed region, vibration or The step-out phenomenon can be made difficult to occur, and the constant speed rotation of the step drive can be stably maintained.

  In this medium speed region, as shown in FIGS. 3, 10, and 11, for example, when the address managed by the electrical angle position management unit 31 is “000” to “039” when the command pulse CWP is input. The excitation pattern selection unit 35 selects a medium speed excitation sequence corresponding to addresses “000” to “039” from the plurality of medium speed excitation sequences stored in the excitation pattern storage unit 34, that is, excitation phases A to The medium-speed excitation sequence having 40 cycles of only the four-phase excitation pattern ABCD in which the four phases of D are excited simultaneously is selected, and the four-phase excitation pattern ABCD is selected for each unit excitation cycle T according to the selected medium-speed excitation sequence. Output to the switching unit 40. As a result, the excitation coils 1a to 1e can generate a torque vector of the four-phase excitation ABCD and position the motor rotor at the full step position.

  When the excitation pattern selection unit 35 receives a sequence switching command from the excitation cycle counter unit 33, it reads the numerical value of the address managed by the electrical angle position management unit 31 and selects the low-speed excitation sequence corresponding to that address. . In this case, when the address of the electrical angle position management unit 31 is “000” to “039”, the same medium speed excitation sequence is selected again by the excitation pattern selection unit 35.

  When the address of the electrical angle position management unit 31 is counted up from “039” to the address “040” corresponding to the full step position by the input of the command pulse CWP, the excitation pattern selection unit 35 receives the address “040”. By selecting the medium speed excitation sequence corresponding to “079”, that is, the medium speed excitation sequence having 40 cycles of only the four phase excitation pattern BCDE in which the four phases of the excitation phases B to E are simultaneously excited. The medium speed excitation sequence is switched (updated).

  Similarly, every time the address of the electrical angle position management unit 31 is changed to an address corresponding to the full step position while repeating the output of the four-phase excitation pattern according to the medium speed excitation sequence, the medium speed excitation sequence. By switching (updating), the stepping motor 1 can be stably driven in full step in the medium speed region, and the combined torque by the four-phase excitation can be ensured appropriately.

  Further, when the stepping motor 1 is driven at full step in the medium speed region, if the rotational speed of the stepping motor 1 is increased in the medium speed region, the impedance of the exciting coil is increased and the current is saturated. (In other words, the first rotation speed (medium speed determination speed) and the second rotation speed (high speed determination speed) are set in advance so that the current is saturated in the medium speed region). In this case, in the present embodiment, the current saturation determination unit 37 of the excitation pattern output unit 30 performs the process of setting the flag 1 and the flag 2 as described above (see FIG. 12), thereby reaching the current saturation state. The time is determined, and the rotation speed managed by the motor rotation speed management unit 32 when the current saturation state is reached is detected and stored as the current saturation rotation speed.

  The excitation pattern selection unit 35 is detected by the current saturation determination unit 37 from three types of high-speed sequence groups of large, medium, and small inductance types (see FIG. 13) stored in the excitation pattern storage unit 34. One high-speed sequence group is selected based on the current saturation rotation speed. In the present embodiment, for example, a case where the current saturation rotation speed is 4.0 rps and a small inductance type high-speed sequence group is selected by the excitation pattern selection unit 35 will be described as an example.

  Further, when the rotation speed of the stepping motor 1 is further increased and the stepping motor 1 is rotated by full step drive in a high speed region where the rotation speed is 5.65 rps (second rotation speed) or more, the rated current is 1. One high-speed excitation based on the rotational speed managed by the motor rotational speed management unit 32 and the address managed by the electrical angle position management unit 31 from the 4A / phase small inductance type high-speed sequence group. Select a sequence.

  For example, when the rotational speed managed by the motor rotational speed management unit 32 is 5.80 rps and the address managed by the electrical angle position management unit 31 is “000”, as shown in FIG. First high-speed excitation sequence 11 corresponding to “000” to “039”, that is, a two-phase excitation pattern BC set in a cycle of “00” to “02”, and a cycle of “03” to “26” A first high-speed excitation sequence 11 having a four-phase excitation pattern ABCD that is set and simultaneously excited in four phases is selected, and each excitation pattern is sequentially turned on every unit excitation cycle T according to the selected high-speed excitation sequence 11. Output.

  In this case, the excitation cycle counter unit 33 outputs an excitation switching command for each unit excitation cycle T and outputs a sequence switching command at intervals corresponding to the number of repetitions of the excitation pattern in the first high-speed excitation sequence 11. .

  When the address of the electrical angle position management unit 31 is counted up from “039” to the address “040” corresponding to the full step position by the input of the command pulse CWP, the excitation pattern selection unit 35 is shown in FIG. The next first high-speed excitation sequence 11 having excitation pattern components corresponding to the addresses “040” to “079” is selected, and the high-speed excitation sequence is switched (updated).

  Similarly, the output of the excitation pattern according to the high-speed excitation sequence is repeated, and the high-speed excitation sequence is switched every time the address of the electrical angle position management unit 31 is changed to an address corresponding to the full step position (update). Thus, the stepping motor 1 can be stably driven in a full step in a high speed region.

  Further, since the first high-speed excitation sequence 11 is formed with the two-phase excitation pattern in which the combined impedance of the entire coil is lower than the four-phase excitation pattern as described above, a current flows through the stepping motor 1. For example, compared with an excitation sequence having only a four-phase excitation pattern, for example, the rate of torque decrease due to current saturation is reduced, and the rotational speed is in a high speed range of 5.65 rps to less than 6.00 rps. Torque can be increased.

  Further, the first high-speed excitation sequence 11 has not only the two-phase excitation pattern BC but also the four-phase excitation pattern ABCD in the cycle after “03” to “20”, thereby causing vibration of the stepping motor 1. It can be made difficult, and the step-out phenomenon can be prevented more effectively.

  Here, a case has been described in which the rotational speed managed by the motor rotational speed management unit 32 is a high-speed region in the range of 5.65 rps or more and less than 6.00 rps, but for example managed by the electrical angle position management unit 31. If the address is “000” and the rotation speed managed by the motor rotation speed management unit 32 is in the range of 6.00 rps to less than 7.63 rps, the second high-speed excitation sequence shown in FIG. 12, that is, the second high-speed excitation having the two-phase excitation pattern BC set in the cycle “00” to “02” and the four-phase excitation pattern ABCD set in the cycle “03” to “20”. Sequence 12 is selected. As a result, similarly to the first high-speed excitation sequence 11, it is possible to increase the torque in the high-speed region where the rotational speed is in the range of 6.00 rps or more and less than 7.63 rps while suppressing the rate of torque decrease due to current saturation. it can.

  When the rotation speed managed by the motor rotation speed management unit 32 is in the range of 7.63 rps or more and less than 9.53 rps, the third high-speed excitation sequence 13 shown in FIG. 2-phase excitation pattern BC set in the cycle, 4-phase excitation pattern ABCD set in the cycle of “01” to “16”, and cycles of “17” to “19” are set to the next full step position. The third high-speed excitation sequence 13 having the two-phase excitation pattern CD to be positioned at is selected.

  As a result, similarly to the first high-speed excitation sequence 11, it is possible to increase the torque in the high-speed region where the rotational speed is in the range of 7.63 rps or more and less than 9.53 rps while keeping the rate of torque decrease with current saturation small. it can. In addition, it is easy to rotate the motor to the next full step position in the high speed region, and it is possible to effectively prevent the rotation of the motor from following the switching of excitation by inputting a command pulse.

  Further, when the rotation speed managed by the motor rotation speed management unit 32 is in the range of 9.53 rps or more and less than 10.17 rps, the two-phase excitation pattern BC, the four-phase excitation pattern ABCD, and the two-phase excitation pattern CD are displayed. When the fourth high-speed excitation sequence 14 having the ratio shown in FIG. 14 is selected and the controlled rotational speed is in the range of 10.17 rps to less than 10.90 rps, the two-phase excitation patterns BC, The fifth high-speed excitation sequence 15 having the phase excitation pattern ABCD and the two-phase excitation pattern CD at the ratio shown in FIG. 14 is selected. Furthermore, when the rotational speed managed by the motor rotational speed management unit 32 is in the range of 10.90 rps or more, the two-phase excitation pattern BC, the three-phase excitation pattern BCD, and the four-phase excitation pattern BCDE are shown in FIG. The sixth high-speed excitation sequence 16 having the indicated ratio is selected.

  Even when the fourth high-speed excitation sequence 14 to the sixth high-speed excitation sequence 16 are selected, the torque in the high-speed region of each rotation speed range can be increased, and the motor in each high-speed region It is easy to rotate to the full step position, and it is possible to effectively prevent the rotation of the motor from following the switching of excitation by inputting a command pulse.

  As another example, FIG. 15 shows five types of high-speed excitation sequences set in the high-speed sequence group of the rated current of 1.4 A / phase and the medium inductance type in this embodiment, and the rated current is 2.8 A. FIG. 16 shows four types of high-speed excitation sequences set in the / phase small inductance type high-speed sequence group.

  In these high-speed sequence groups and other types of high-speed sequence groups as well, each high-speed excitation sequence is positioned at one full-step position, as in the case of the 1.4 A / phase small inductance type high-speed sequence group. There are two-phase excitation excitation patterns (for example, two-phase excitation pattern BC) and other multi-phase excitation excitation patterns.

  Accordingly, in any high-speed sequence group corresponding to the motor characteristics of the stepping motor 1, it is possible to stably and effectively extend the torque in the high-speed region. Further, when the high-speed excitation sequence is switched, the stepping motor The vibration of 1 can be made difficult and the step-out phenomenon can be effectively prevented, and the rotation of the motor can be prevented from following the switching of excitation by the input of the command pulse. The same effect as in the case of the high-speed sequence group of / phase small inductance type can be obtained.

  Next, as a driving device for the stepping motor 1 according to the second embodiment of the present invention, a constant current control is performed using a motor drive voltage conversion type (hereinafter referred to as the output stage chopper type according to the first embodiment described above). , A driving device 20 that is abbreviated as DV type) will be described with reference to FIG.

  The drive device 20 according to the second embodiment includes an excitation pattern output unit 60 that receives an instruction pulse CWP or CCWP and outputs an excitation pattern for exciting the excitation coils 1a to 1e of the five-phase stepping motor 1. It has the switching part 40 as an output stage which has several switching element (power element) TR1-TR10, and the motor current control part 70 which performs DV type constant current control. In this case, since the switching unit 40 is configured in the same manner as the switching unit 40 according to the first embodiment described above, detailed description thereof will be omitted here.

  The motor current control unit 70 according to the second embodiment performs DV type constant current control. The motor current control unit 70 supplies a power source PS2 that supplies power for exciting the excitation coils 1a to 1e of the five-phase stepping motor 1, a first capacitor C2a that smoothes the voltage of the power source PS2, and excitation coils 1a to 1e. First and second current detection resistors R2a and R2b that detect a flowing current, a PWM constant current control circuit 71 that performs constant current control based on the detected current, and a switching element TR11 that can be switched ON / OFF Generated by PWM, a power element drive circuit 72 that switches ON / OFF of the switching element TR11 based on an output signal from the PWM constant current control circuit 71, a diode D11 that bypasses the electromotive force generated by the exciting coils 1a to 1e, and Choke co that generates intermittent motor voltage by inputting intermittent voltage With Le and L2 and the second capacitor C2b, an A / D converter 73 to send a motor driving voltage and digitizes the excitation pattern output unit 60.

  In this case, the PWM constant current control circuit 71 generates a difference between the current flowing in the exciting coils 1a to 1e and the reference current as an error signal, and controls ON / OFF of the switching element TR11. Thereby, the voltage supplied to the exciting coils 1a to 1e can be adjusted, and the total current for the exciting coil of the stepping motor 1 can be controlled to be a predetermined current.

  For example, when the current flowing through the first and second current detection resistors R2a and R2b decreases, the level of the error signal increases, so that the on-time of the switching element TR11 is lengthened by the PWM constant current control circuit 71. As a result, the voltage passing through the switching element TR11 is smoothed by the choke coil L2 and the second capacitor C2b and becomes a high voltage, which is applied to the exciting coils 1a to 1e. Therefore, control for increasing the exciting voltage is performed. Can do.

  On the other hand, when the current flowing through the first and second current detection resistors R2a and R2b increases, the level of the error signal decreases, so that the on-time of the switching element TR11 is shortened to reduce the excitation voltage. Do. Thus, by appropriately adjusting the excitation voltage of the five-phase stepping motor 1 using the motor current control unit 70, the excitation current is stabilized regardless of the unit excitation cycle T managed by the excitation cycle counter unit 63. The 5-phase stepping motor 1 can be driven with a constant current.

  The excitation pattern output unit 60 according to the second embodiment includes an electrical angle position management unit 61 that counts input command pulses and manages an address corresponding to the electrical angle position, and a stepping motor based on the command pulse count. A motor rotation speed management unit 62 that manages one rotation speed, an excitation cycle counter unit 63 that manages a constant unit excitation cycle T, an excitation pattern storage unit (memory) 64 that stores a plurality of excitation sequences, and an excitation pattern An excitation pattern selection unit 65 that selects one excitation sequence from the storage unit 64 and outputs an excitation pattern according to the excitation sequence, and a current saturation determination unit 67 that determines that the current flowing through the excitation coil is saturated.

  In this case, the electrical angle position management unit 61, the motor rotation speed management unit 62, the excitation cycle counter unit 63, and the excitation pattern selection unit 65 are each processing unit of the excitation pattern output unit 30 according to the first embodiment described above. Therefore, detailed description thereof will be omitted here.

  Further, in the driving device 20 of the second embodiment, since the DV type constant current control is performed as described above, the current saturation determination unit 67 determines the excitation / non-excitation state in the motor current control unit 70. As in the case of the first embodiment described above, the flag 1 and the flag 2 are set to detect the time when the current reaches the saturation state, and the rotation speed at that time is set to the current saturation rotation. Store in memory as speed. In this case, since the motor current control unit 70 is provided with a smoothing circuit, the state in which the current is saturated can be detected more stably than in the case of the output stage chopper type in the first embodiment described above. Is possible.

  Further, in the memory of the excitation pattern output unit 60, for example, a rotation speed of 1.5 rps is set as a medium speed determination speed (first rotation speed), and as a high speed determination speed (second rotation speed), for example, A rotation speed of 5.65 rps is set.

  In the excitation pattern output unit 60 according to the second embodiment, instead of setting a predetermined speed (1.5 rps) as the medium speed determination speed, the stepping as described in the first embodiment is used. It is also possible to provide a medium speed determination unit that determines that the rotation speed of the motor is in the medium speed region.

  In this case, the medium speed determination unit according to the second embodiment determines whether or not the excitation duty ratio of the excitation output exceeds 70%, and when the ratio exceeds 70%, the medium speed first determination that sets the flag 1 is performed. And a medium-speed second determination unit that checks the state of flag 1 and sets flag 2 when flag 1 is set in three unit excitation cycles T. Therefore, the medium speed determination unit determines that the rotation speed is in the medium speed region when the state where the flag 1 is set is maintained in the unit excitation period T of three times, and the excitation pattern selection unit 35 determines the medium speed. An area signal can be output.

  Since the driving device 20 of the second embodiment performs DV type constant current control, the current saturation state can be detected more stably than in the case of the output stage chopper type in the first embodiment described above. it can. Therefore, in the second embodiment, the medium speed determination speed (first rotation speed) can be set to 1.5 rps (or a value slightly larger than 1.5 rps) similar to the first embodiment described above. When the medium speed determination unit is provided, the determination criterion for the excitation duty ratio when setting the flag 1 in the medium speed first determination unit is larger than 60% in the case of the first embodiment described above. It can be set to 70%. Thereby, before the current is saturated, it is possible to stably switch from the micro step drive in the low speed region to the full step drive in the medium speed region, and faster than the case of the output stage chopper type in the first embodiment. It becomes possible to perform microstep driving up to the rotational speed.

  The excitation pattern storage unit 64 according to the second embodiment includes a low-speed excitation sequence for a low speed region in which the rotation speed of the stepping motor 1 is less than a predetermined first rotation speed (medium speed determination speed, for example, 1.5 rps). A medium speed excitation sequence for a medium speed region in which the rotation speed of the stepping motor 1 is equal to or higher than the first rotation speed and less than a predetermined second rotation speed (high speed determination speed, for example, 5.65 rps); A high-speed sequence group having a plurality of high-speed excitation sequences for a high-speed region in which the rotation speed is equal to or higher than the second rotation speed is stored.

  In this case, the low-speed excitation sequence is an excitation sequence in which the stepping motor 1 is positioned at each step position of the full step position and the microstep position so that the stepping motor 1 is microstep driven in the low speed region.

  For example, when the resolution is 1/40, 400 kinds of low speeds corresponding to addresses “000” to “399” are used as shown in FIGS. An excitation sequence is set and stored. Each low-speed excitation sequence has a plurality of two-phase excitation patterns combined so as to be positioned at the electrical angle position of each address. Each excitation pattern is an excitation output from the excitation cycle counter unit 63. Switching is performed based on the switching command.

  In this case, the low-speed excitation sequence corresponding to the address of the full step position (for example, “000”) is formed by a combination of two two-phase excitation excitation patterns in order to realize four-phase excitation by synthesis. On the other hand, the low-speed excitation sequence corresponding to the address of the microstep position (for example, “001” to “039”) includes a first combination excitation pattern obtained by combining two two-phase excitation patterns at one full step position, A second combined excitation pattern obtained by combining two two-phase excitation patterns at the next full step position is combined at a ratio corresponding to the step position.

  More specifically, the low-speed excitation sequence corresponding to the address “000” of the full step position is set by combining the excitation pattern BC and the excitation pattern AD in the same number or time ratio (excitation duty ratio). Thus, a four-phase excitation ABCD by synthesis is realized.

  Further, the low-speed excitation sequence corresponding to the address “040” of the next full-step position is set by combining the excitation pattern CD and the excitation pattern BE in the same number of times or time ratio, thereby 4 Realize phase excitation BCDE. Similarly, the low-speed excitation sequence corresponding to each address of the full step position has two two-phase excitation patterns that realize four-phase excitation by synthesis at the same number or time ratio.

  In addition, each low-speed excitation sequence corresponding to the microstep position addresses “001” to “039” set between addresses “000” and “040” realizes four-phase excitation ABCD at the full step position. First combination excitation pattern BC-AD, which combines two two-phase excitation patterns, and second combination excitation pattern CD-, which combines two two-phase excitation patterns that realize four-phase excitation BCDE at the next full-step position. BE is set in combination at a ratio corresponding to the step position.

  In this case, as the numerical value of the address increases, the number or time ratio of the first combination excitation pattern BC-AD is gradually decreased and the number or time ratio of the second combination excitation pattern CD-BE is gradually increased. Each low-speed excitation sequence at the microstep position is set. Similarly, after the address “041”, the first combination excitation pattern and the second combination excitation pattern corresponding to each address of the microstep position are combined at a predetermined ratio to correspond to each microstep position. Low speed excitation sequence is set.

  Further, the medium-speed excitation sequence in the second embodiment is an excitation sequence for positioning at each full-step position so that the stepping motor 1 is driven in full-step in the medium-speed region. Ten types of medium-speed excitation sequences for positioning at each full step position are stored (see FIGS. 3 and 5).

  Each medium speed excitation sequence has only a four-phase excitation pattern that realizes four-phase excitation corresponding to each full-step position by exciting the four phases simultaneously. For example, the medium-speed excitation sequence corresponding to addresses “000” to “039” positioned at one full step position when the command pulse CWP is input (CW direction) is excitation phase A, excitation phase B, and excitation phase C. , And the four-phase excitation pattern ABCD in which the four phases of the excitation phase D are simultaneously excited, and a torque vector of VA + VB + VC + VD is formed by this four-phase excitation pattern ABCD.

  The medium-speed excitation sequence corresponding to the next addresses “040” to “079” is a four-phase excitation pattern in which four phases of excitation phase B, excitation phase C, excitation phase D, and excitation phase E are excited simultaneously. Has only BCDE. Thereafter, similarly, each medium speed excitation sequence has only a four-phase excitation pattern for positioning to the corresponding full step position.

  Further, in the excitation pattern storage unit 64, a plurality of high-speed sequence groups corresponding to motor characteristics based on the inductance of the stepping motor 1 (for example, three types of high-speed sequence groups corresponding to large, medium, and small inductance types) are stored in advance. While being stored (see FIG. 13), each high-speed sequence group has a plurality of high-speed excitation sequences corresponding to a predetermined rotation speed range in the high-speed region.

  Each high-speed sequence group is set with a plurality of high-speed excitation sequences corresponding to the rotational speed range managed by the motor rotational speed management unit 62. For example, the rated current is as small as 1.4 A / phase. As in the case of the first embodiment, six types of excitation sequences of the first high-speed excitation sequence to the sixth high-speed excitation sequence are set in the inductance type high-speed sequence group.

  In this case, the first high-speed excitation sequence to the sixth high-speed excitation sequence are excitation sequences that are selected when the rotation speed of the stepping motor 1 is within a predetermined rotation speed range. The high-speed excitation sequence is selected in a different rotational speed range from the first high-speed excitation sequence to the sixth high-speed excitation sequence in the case of the first embodiment.

  Further, each high-speed excitation sequence in the 1.4 A / phase small-inductance type high-speed sequence group includes two-phase excitation excitation patterns (for example, two-phase excitation pattern BC) positioned at one full step position, and other various excitation sequences. It is formed by a combination with an excitation pattern of phase excitation (see FIGS. 4 and 6). In this case, the two-phase excitation pattern (two-phase excitation pattern BC) positioned at one full-step position is the first stage of each high-speed excitation sequence (that is, the first repetition number or the first several repetitions, or Time ratio on the first side).

  Further, as other multi-phase excitation patterns combined with the above-described two-phase excitation pattern, as in the case of the first embodiment, a four-phase excitation pattern in which four phases are simultaneously excited and positioned at the full step position. Two-phase excitation pattern for positioning at the next full step position, four-phase excitation pattern for simultaneously exciting four phases and positioning at the next full step position, and positioning at a half step position between the two full step positions 3 At least one excitation pattern among the phase excitation patterns is combined according to the rotation characteristics and rotation speed of the stepping motor 1 and the usage of the stepping motor 1.

  Further, the excitation length of the entire sequence in each high-speed excitation sequence (that is, the number of excitation pattern repetitions or the excitation time) is the same as in the case of the first embodiment described above. The excitation length of the entire sequence is made shorter as the high-speed excitation sequence has a higher rotational speed range.

  As described above, in the drive device 20 according to the second embodiment, a plurality of excitation sequences corresponding to the rotation speed and address of the stepping motor 1 are stored in the excitation pattern storage unit 64, and the excitation pattern selection unit Reference numeral 65 denotes a rotation speed managed by the motor rotation speed management unit 62 among a plurality of excitation sequences stored in the excitation pattern storage unit 64 and an address (electrical angle position) managed by the electrical angle position management unit 61. An appropriate excitation sequence can be selected based on the above.

Next, a method of step-driving the stepping motor 1 having a rated current of 1.4 A / phase using the driving device 20 of the second embodiment described above will be described.
When the command pulse CWP or CCWP is input to the excitation pattern output unit 60, the electrical angle position management unit 61 counts up the numerical value of the address every time the command pulse CWP is input, and the command pulse CCWP is input. Each time, the numerical value of the address is counted down to manage the numerical value, and the numerical value of the address is output to the motor rotation speed management unit 62 and the excitation pattern selection unit 65. Further, the motor rotation speed management unit 62 manages the rotation speed of the stepping motor 1 from the number of pulse inputs per unit time, and outputs a numerical value of the managed rotation speed to the excitation pattern selection unit 65.

  The excitation cycle counter unit 63 of the excitation pattern output unit 60 manages a constant unit excitation cycle T that is not related to the command pulse, and outputs an excitation switching command to the excitation pattern selection unit 65 every unit excitation cycle T. . Further, the excitation cycle counter unit 63 outputs a sequence switching command to the excitation pattern selection unit 65 every fixed sequence cycle ST (a cycle that is an integral multiple of the unit excitation cycle T).

  In the excitation pattern selection unit 65 of the excitation pattern output unit 60, the rotation speed output from the motor rotation speed management unit 62 and the electrical angle position management unit among the plurality of excitation sequences stored in the excitation pattern storage unit 64. Based on the address value output from 61, an excitation sequence that meets the conditions is selected, and an excitation pattern is sequentially output for each unit excitation period T according to the selected excitation sequence. As a result, the switching unit 40 switches the excitation for the five excitation coils 1a to 1e by controlling ON and OFF of the switching elements TR1 to TR10 in accordance with the excitation pattern output from the excitation pattern selection unit 65, thereby switching the stepping motor. 1 can be step-driven.

  For example, when the stepping motor 1 is rotated in the low speed region, if the address managed by the electrical angle position management unit 61 is “000”, the excitation pattern selection unit 65 is stored in the excitation pattern storage unit 64. The low-speed excitation sequence corresponding to the address “000”, that is, the low-speed excitation sequence in which the two-phase excitation pattern BC and the two-phase excitation pattern AD are combined at the same number or time ratio is selected. The excitation pattern is output to the switching unit 40 while switching the excitation pattern for each unit excitation period T according to the selected low-speed excitation sequence.

  Thus, in the exciting coils 1a to 1e, two sets of excitation pattern BC and excitation pattern AD are alternately repeated to generate a combined torque vector of four-phase excitation ABCD, and the motor rotor is set to the address “000”. It can be positioned at the full step position.

  Then, when the excitation pattern output according to the low speed excitation sequence corresponding to the address “000” is performed in a predetermined cycle or a predetermined time, the excitation pattern selection unit 65 issues a sequence switching command from the excitation cycle counter unit 63. In response, the numerical value of the address managed by the electrical angle position management unit 61 is read, and the low-speed excitation sequence is updated (switched) by selecting the low-speed excitation sequence corresponding to the address.

  In the same manner, the output of the excitation pattern according to the excitation sequence for low speed is performed in a predetermined cycle or time, and each time the sequence switching command is received, the low speed corresponding to the address managed by the electrical angle position management unit 61 is received. By updating (switching) the excitation sequence, the stepping motor 1 can be stably driven in microsteps in a low speed region. Further, in the second embodiment, the low-speed excitation sequence is updated every time the sequence switching command is received, and the address of the electrical angle position management unit 61 corresponds to the full step position by the input of the command pulse CWP or CCWP. Every time the address is switched, the low-speed excitation sequence is updated.

  Thereby, the stepping motor 1 can be more stably microstep driven in the low speed region, and an appropriate torque can be stably secured. Further, for example, even when the rotation speed of the stepping motor 1 is increased in the low speed region, it is possible to prevent the excitation sequence corresponding to the full step position address from being thinned out when the excitation sequence is updated, and the micro step position address. The microstep drive can be smoothly performed by reducing the thinning of the excitation sequence corresponding to.

  Next, when the stepping motor 1 is rotated in the medium speed region, the step driving of the stepping motor 1 is switched from the micro step driving in the low speed region to the full step driving. In this case, the excitation sequence is updated every time the sequence switching command is received as described above, and every time the address of the electrical angle position management unit 61 is switched to an address corresponding to the full step position. As in the first embodiment described above, when switching from the micro step drive in the low speed region to the full step drive in the medium speed region, it is possible to make it difficult for vibration and step-out phenomenon to occur, Constant speed rotation can be stably maintained.

  In this medium speed region, for example, when the address managed by the electrical angle position management unit 61 at the time of inputting the command pulse CWP (CW direction) is “000” to “039”, the excitation pattern selection unit 65 From a plurality of medium speed excitation sequences stored in the pattern storage unit 64, medium speed excitation sequences corresponding to addresses "000" to "039", that is, four phases of excitation phases A to D are excited simultaneously. The medium-speed excitation sequence having only the four-phase excitation pattern ABCD is selected, and the four-phase excitation pattern ABCD is output to the switching unit 40 in accordance with the selected medium-speed excitation sequence. Thus, the excitation coils 1a to 1e can generate the torque vector (VA + VB + VC + VD) of the four-phase excitation ABCD and position the motor rotor at the full step position.

  When the address of the electrical angle position management unit 61 is counted up from “039” to the address “040” corresponding to the full step position by the input of the command pulse CWP, the excitation pattern selection unit 65 sets the address “040”. By selecting the medium speed excitation sequence corresponding to “079”, that is, the medium speed excitation sequence having only the four phase excitation pattern BCDE in which the four phases of the excitation phases B to E are simultaneously excited. The excitation sequence is switched.

  Similarly, every time the address of the electrical angle position management unit 61 is changed to an address corresponding to the full step position while repeating the output of the four-phase excitation pattern according to the medium speed excitation sequence, the medium speed excitation sequence. By switching between, the stepping motor 1 can be stably driven in a full step in the medium speed region, and the combined torque by the four-phase excitation can be appropriately secured.

  When the current is saturated in the medium speed region, the current saturation determination unit 67 of the excitation pattern output unit 60 performs processing for setting the flag 1 and the flag 2 as in the case of the first embodiment. . As a result, the time when the current saturation state is reached is determined, and the rotation speed managed by the motor rotation speed management unit 62 when the current saturation state is reached is detected and stored as the current saturation rotation speed.

  The excitation pattern selection unit 65 is detected by the current saturation determination unit 67 from three types of high-speed sequence groups of large, medium, and small inductance types (see FIG. 13) stored in the excitation pattern storage unit 64. One high-speed sequence group is selected based on the current saturation rotation speed. In the second embodiment, for example, a case where the current saturation rotation speed is 4.0 rps and a small-inductance type high-speed sequence group is selected by the excitation pattern selection unit 65 will be described as an example.

  When the stepping motor 1 is rotated in the high-speed region, the excitation pattern selection unit 65 selects the rotation speed managed by the motor rotation speed management unit 62 from the small inductance type high-speed sequence group having a rated current of 1.4 A / phase. Based on the address managed by the electrical angle position management unit 61, one high-speed excitation sequence is selected.

  For example, when the address managed by the electrical angle position management unit 61 is “000” and the rotation speed managed by the motor rotation speed management unit 62 is within a predetermined rotation speed range, the excitation pattern selection unit 65 selects a first high-speed excitation sequence having a two-phase excitation pattern BC and a four-phase excitation pattern ABCD in which the four phases are excited simultaneously, and unitizes each excitation pattern in accordance with the selected high-speed excitation sequence. Output in turn every T.

  Further, when the rotation speed managed by the motor rotation speed management unit 62 is larger than the predetermined rotation speed range, the second high-speed excitation sequence to the sixth high-speed excitation sequence are selected based on the rotation speed. Thus, one corresponding high-speed excitation sequence is selected.

  As a result, as in the case of the first embodiment, it is possible to stably and effectively increase the torque in each speed range of the high-speed region. Further, when the high-speed excitation sequence is switched, stepping is performed. The vibration of the motor 1 can be made difficult to occur, the step-out phenomenon can be effectively prevented, and the motor rotation can be prevented from following the switching of excitation by inputting a command pulse. .

  As Example 1, the output stage chopper type drive device 10 (see FIG. 1) of the present invention according to the first embodiment described above and a four-phase excitation pattern for exciting four phases simultaneously in the medium speed region and the high speed region. The conventional driving device that drives the stepping motor in a full step only with a stepping motor with a rated current of 1.4 A / phase (small inductance type) was applied.

  In this case, the stepping motor was step-driven at various rotational speeds, and the torque characteristics of the stepping motors obtained by the two driving devices were compared by measuring the torque of the stepping motor obtained at a predetermined rotational speed.

  FIG. 18 is a graph in which the torque characteristics of the stepping motor obtained using the driving device 10 of the present invention and the torque characteristics of the stepping motor obtained using the conventional driving device are superimposed. Here, the horizontal axis of the graph of FIG. 18 represents the rotational speed (rpm) per minute, and the vertical axis represents the magnitude (N · m) of the torque of the stepping motor obtained at each rotational speed. . In the graph, the torque characteristics of the stepping motor obtained using the driving device 10 of the present invention are indicated by a solid line, and the torque characteristics of the stepping motor obtained using the conventional driving device are indicated by a dotted line.

  As shown in FIG. 18, the excitation sequence does not change between the driving device 10 of the present invention and the conventional driving device (for example, the region where the rotational speed is greater than 0 rpm and less than 90 rpm), the medium speed region ( For example, in the region where the rotation speed is 90 rpm or more and less than 339 rpm, the torque of the stepping motor obtained by these two driving devices did not change. On the other hand, in the high speed region where the rotational speed is 339 rpm or more (particularly, the region where the rotational speed is 600 rpm or more), the use of the driving device 10 of the present invention can provide a larger torque than when using the conventional driving device. Was confirmed.

  Further, it was found that when using the driving device 10 of the present invention that can obtain a larger torque in the high speed region, the speed can be increased by about 1.5 times compared to the case of using the conventional driving device. . If such a high speed can be achieved, for example, with the driving device 10 of the present invention of the DC24V input type that is not subject to the constant voltage command, high-speed characteristics equivalent to the conventional driving device of the DC36V input type can be obtained. Become.

  As Example 2, the output stage chopper type driving device 10 of the present invention according to the first embodiment described above and the conventional driving in which the stepping motor is driven in a full step with only the four-phase excitation pattern in the medium speed region and the high speed region. The torque characteristics of the stepping motor obtained when the apparatus was applied to a stepping motor (medium inductance type) with a rated current of 1.4 A / phase were compared.

  FIG. 19 shows a graph in which the torque characteristics (solid line) of the stepping motor obtained using the driving device 10 of the present invention and the torque characteristics (dotted line) of the stepping motor obtained using the conventional driving device are superimposed.

  As shown in FIG. 19, in a low speed region (for example, a region where the rotation speed is greater than 0 rpm and less than 90 rpm) and a medium speed region (for example, a region where the rotation speed is 90 rpm or more and less than 339 rpm), it is obtained with two driving devices. Although the torque did not change, it was confirmed that, in the high speed region where the rotational speed is 339 rpm or more, it is possible to obtain a larger torque than when the conventional driving device is used by using the driving device 10 of the present invention.

  As Example 3, the output stage chopper type driving device 10 of the present invention according to the first embodiment described above and the conventional driving in which the stepping motor is driven in a full step with only the four-phase excitation pattern in the medium speed region and the high speed region. The torque characteristics obtained when the apparatus was applied to the same stepping motor (small inductance type) having a rated current of 2.8 A / phase were compared.

  FIG. 20 shows a graph in which the torque characteristics (solid line) of the stepping motor obtained using the driving apparatus 10 of the present invention and the torque characteristics (dotted line) of the stepping motor obtained using the conventional driving apparatus are superimposed. In this case, the conventional drive device shows the torque characteristics obtained when an excitation current of 2.8 A / phase is output to the stepping motor, whereas the drive device 10 of the present invention outputs an excitation current of 2 This shows the torque characteristics obtained when the setting is as low as 4 A / phase.

  As shown in FIG. 20, due to the difference in the magnitude of the output current, in the low speed region and the medium speed region where the rotational speed is less than 600 rpm, the conventional drive device has a larger torque than the drive device 10 of the present invention. Has been obtained. On the other hand, when the rotational speed is higher than 600 rpm, by using the driving device 10 of the present invention, even when the current is set to 0.4 A / phase less than the rated current of the stepping motor, the conventional current is output. It was confirmed that a larger torque than that of the driving device could be obtained. That is, according to the driving apparatus 10 of the present invention, it was confirmed that a large torque can be obtained even if the excitation current to be output is small.

  As Example 4, the DV-type drive device 20 (see FIG. 17) of the present invention according to the second embodiment described above and the stepping motor is driven in a full step with only the four-phase excitation pattern in the medium speed region and the high speed region. The torque characteristics of the stepping motor obtained when the conventional driving device is applied to a stepping motor having a rated current of 1.4 A / phase (medium inductance type) were compared.

  FIG. 21 shows a graph in which the torque characteristics (solid line) of the stepping motor obtained using the driving device 20 of the present invention and the torque characteristics (dotted line) of the stepping motor obtained using the conventional driving device are superimposed.

  As shown in FIG. 21, in the driving device 20 of the present invention and the conventional driving device, the torque obtained in the low speed region and the medium speed region is the same as in the first and second embodiments. In the high-speed region, it was confirmed that by using the driving device 20 of the present invention, a larger torque can be obtained than when the conventional driving device is used.

DESCRIPTION OF SYMBOLS 1 Stepping motor 1a-1e Excitation coil 10 Drive apparatus 11 1st high speed excitation sequence 12 2nd high speed excitation sequence 13 3rd high speed excitation sequence 14 4th high speed excitation sequence 15 5th high speed excitation sequence 16 6th high speed Excitation sequence 20 Drive unit 30 Excitation pattern output unit 31 Electrical angle position management unit (address counter)
32 Motor rotation speed management part (speed measurement counter)
33 Excitation period counter unit 34 Excitation pattern storage unit (memory)
35 Excitation pattern selection unit 36 Excitation / non-excitation processing unit 37 Current saturation determination unit 40 Switching unit (output stage)
41 Power element drive circuit 50 Motor current control unit 51 PWM constant current control circuit 60 Excitation pattern output unit 61 Electrical angle position management unit 62 Motor rotation speed management unit 63 Excitation cycle counter unit 64 Excitation pattern storage unit (memory)
65 Excitation pattern selection section 67 Current saturation determination section 70 Motor current control section 71 PWM constant current control circuit 72 Power element drive circuit 73 A / D converter A, a Direction of excitation current flowing in the excitation coil B, b Flow in the excitation coil Direction of excitation current C, c Direction of excitation current flowing in excitation coil D, d Direction of excitation current flowing in excitation coil E, e Direction of excitation current flowing in excitation coil CWP, CCWP Command pulse C1 Capacitor C2a First capacitor C2b First 2 capacitors D1 to D11 Diodes L2 Choke coils OUT1 to OUT5 Output terminals PS1 and PS2 Power supply R1 Current detection resistor R2a First current detection resistor R2b Second current detection resistor T Unit excitation cycle TR1 to TR11 Switching element (power element)
VA, Va Torque vector VB, Vb Torque vector VC, Vc Torque vector VD, Vd Torque vector VE, Ve Torque vector

Claims (11)

A stepping motor drive device that switches the excitation phase of an HB type five-phase stepping motor, in which five excitation coils are connected in a ring, by inputting a command pulse, and step-drives the stepping motor, counting the command pulse A motor rotation management unit for managing the electrical angle position and rotation speed of the stepping motor, an excitation pattern storage unit for storing an excitation sequence having a plurality of excitation patterns, and an electrical angle position managed by the motor rotation management unit And an excitation pattern selection unit that selects the corresponding excitation sequence based on the rotation speed from the excitation pattern storage unit, and a plurality of switching elements, and the excitation pattern of the excitation sequence selected by the excitation pattern selection unit By controlling ON / OFF of each switching element according to The drive device for a stepping motor and a switching unit for switching the excitation phase of said stepping motor,
A plurality of high-speed excitations that are set in the excitation pattern storage unit in combination with an excitation pattern of two-phase excitation in which the synthetic impedance of the excitation phase is lower than an excitation pattern of four-phase excitation and other multi-phase excitation excitation patterns Excitation sequence is stored,
The excitation pattern selection unit is a high-speed region in which the rotation speed managed by the motor rotation management unit is equal to or higher than a predetermined high-speed determination speed faster than a current saturation rotation speed at which a current flowing through the stepping motor is saturated. Pre-set to select the high-speed excitation sequence corresponding to the electrical angle position,
A driving device for a stepping motor. A plurality of medium-speed excitation sequences having only four-phase excitation excitation patterns are stored in the excitation pattern storage unit,
The excitation pattern selection unit corresponds to the electrical angle position when the rotation speed is a medium speed region that is equal to or higher than a predetermined medium speed determination speed that is lower than the current saturation rotation speed and less than the high speed determination speed. Pre-set to select the medium speed excitation sequence,
The stepping motor drive device according to claim 1.   3. The stepping motor drive according to claim 1, wherein the high-speed excitation sequence is set by combining the excitation pattern of the two-phase excitation with the excitation pattern of the four-phase excitation and / or the excitation pattern of the three-phase excitation. apparatus. A high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotation speed range of the high-speed region is stored in the excitation pattern storage unit,
The excitation pattern selection unit is preset to select the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotation speed.
The drive device for stepping motors in any one of Claims 1-3.   5. The stepping motor drive device according to claim 4, wherein each high-speed excitation sequence of the high-speed sequence group is configured such that the excitation length of the entire sequence is set shorter as the rotational speed range becomes higher.   The high-speed excitation sequence selected when the rotation speed is equal to or higher than a predetermined super-high-speed determination speed faster than the high-speed determination speed is an excitation pattern that forms a torque vector corresponding to one full step position, and the next 6. The stepping according to claim 4, further comprising: an excitation pattern that forms a torque vector corresponding to a full step position and / or an excitation pattern that forms a torque vector corresponding to a half step position between both full step positions. Motor drive device. A current saturation determination unit that determines that the current flowing through the stepping motor is saturated and detects the current saturation rotation speed;
In the excitation pattern storage unit, a plurality of the high-speed sequence groups corresponding to the speed range of the current saturation rotation speed are stored in advance,
The excitation pattern selection unit is preset to select one high-speed sequence group corresponding to the detected current saturation rotation speed from a plurality of high-speed sequence groups.
The stepping motor drive device according to any one of claims 3 to 6. A stepping motor driving method in which the excitation phase of an HB type five-phase stepping motor in which five excitation coils are connected in a ring shape is switched by inputting a command pulse, and the stepping motor is step-driven.
A plurality of high-speed excitation sequences set by combining two-phase excitation excitation patterns whose combined impedance of excitation phases is lower than that of four-phase excitation and other multi-phase excitation excitation patterns are stored as excitation patterns. In a high-speed region in which the rotation speed managed by the motor rotation management unit is equal to or higher than a predetermined high-speed determination speed faster than a current saturation rotation speed at which a current flowing in the stepping motor is saturated. Sometimes selecting the high-speed excitation sequence corresponding to the electrical angle position,
A stepping motor driving method comprising: Storing a plurality of medium speed excitation sequences having only four-phase excitation excitation patterns in the excitation pattern storage unit; and
The medium speed excitation sequence corresponding to the electrical angle position when the rotation speed is a medium speed region that is equal to or higher than a predetermined medium speed determination speed that is lower than the current saturation rotation speed and less than the high speed determination speed. To choose,
The stepping motor drive method according to claim 8, comprising: Storing in advance in the excitation pattern storage unit a high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotation speed range of the high-speed region; and
Selecting the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotation speed in the high-speed region;
A stepping motor drive method according to claim 8 or 9, comprising: A plurality of the high-speed sequence groups corresponding to the speed range of the current saturation rotation speed are stored in advance in the excitation pattern storage unit;
Determining that the current flowing through the stepping motor is saturated and detecting the current saturation rotation speed; and
Selecting one high-speed sequence group corresponding to the detected current saturation rotational speed from a plurality of the high-speed sequence groups;
The stepping motor drive method according to claim 10 comprising:

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