JP2008182816A - Stepping motor driving device, precision measuring equipment, precision machining equipment, and microstep driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use a conventional electronic circuit to segment the resolution of a stepping motor, and at the same time to reduce a grating audible sound produced at the time of rotational driving and at the time of hold. <P>SOLUTION: A stepping motor driving device includes: an electrical angle position managing means 12a having a basic step counter for counting the number of times of stepping of a stepping motor in a basic step and a number of times dividing step counter for counting the number of times of stepping in number of times divided step, obtained by dividing a basic step angle by m; an excitation phase combination outputting means 12b for outputting a combination of a first excitation set (F1-F2) and a second excitation set (F3-F4) according to the number of times of stepping in basic step; a number of times of excitation ratio outputting means 12d that gradually increases or decreases the number of times of exciting the first excitation set and gradually decreases or increases the number of times of exciting the second excitation set according to the number of times of stepping in number of times dividing step and thereby determines the ratio of the number of times of excitation of the first excitation set to that of the second excitation set; and an excitation waveform outputting means 12e that successively outputs excitation waveform dispersed so that the first excitation set does not constantly occur relative to the second excitation set in a simple cycle with a predetermined ratio of the number of times of excitation maintained, in an excitation cycle T. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, when exciting an exciting coil of an N-phase stepping motor having a plurality of exciting coils such as a star connection and an annular connection, the excitation ratio between one excitation combination and another excitation combination is changed to The present invention relates to a stepping motor driving device that subdivides a basic step angle α of a phase stepping motor, a precision measuring device and a precision processing device equipped with the device, and a microstep driving method thereof.

  Generally, when driving a motor rotor of an N-phase stepping motor, a rotation command pulse is input from the outside to the stepping motor drive device, and the drive device counts the input rotation command pulse, and the count value In response to this, by exciting a predetermined excitation phase of the N-phase stepping motor, control is performed to rotate the motor rotor by an angle proportional to the total number of rotation command pulses.

  In order to refine the positioning resolution of the motor rotor of this N-phase stepping motor, the half-step drive that divides the basic step angle α determined from the mechanical structure of the N-phase stepping motor in half, or a smaller angle Then, microstep driving for positioning is performed.

  As an example of a conventional microstep driving method, for example, Japanese Patent No. 3725316 (Patent Document 1) discloses that one basic step of a motor rotor is selected from five excitation phases formed in a five-phase stepping motor. One excitation combination for positioning to the position (hereinafter referred to as the first excitation set) and another excitation combination for positioning to the position of the next basic step (hereinafter referred to as the second excitation set) And by changing a part of the four excitation patterns combining the first excitation group or the second excitation group according to the order of the microstep angles, and changing the ratio of the number of excitations, A microstep driving method for subdividing the basic step angle α is shown.

  In the driving method of the five-phase stepping motor described in Example 2 of Patent Document 1, an excitation set (BC) that simultaneously excites two phases, for example, excitation phase B and excitation phase C, among the five excitation phases is generated. At the same time, an excitation set (AD) for exciting the excitation phase A and the excitation phase D simultaneously is generated. Then, an excitation sequence using four types of excitation groups (BC), (AD), (BC), and (AD) is generated, and this is repeatedly output to form a composite vector << ABCD >> = 0 Basic step positioning is realized.

  When stepping microsteps from address = 0 to address = 1, the last excitation group (AD) of the four types of excitation groups (BC), (AD), (BC), and (AD) is excited. By generating an excitation sequence using the four types of excitation groups (BC), (AD), (BC), and (CD) replaced with the group (CD), and repeatedly outputting them, the resultant vector << ABCD >> + 9 .7 ° is obtained and positioned at address = 1.

  Also, when stepping from address = 1 to address = 2, the third excitation group (BC) of the four types of excitation groups (BC), (AD), (BC), and (CD) is excited. Generate an excitation sequence using four types of excitation groups (BC), (AD), (CD), and (BE), which are replaced with the group (CD), and finally the excitation group (BE), and repeat this By outputting, a composite vector << ABCDE >> is obtained and positioned at the half step position of address = 2.

In addition, when the micro step is incremented from the address = 2 to the address = 3, except for the second excitation group (AD), the last four excitation groups (CD) are arranged (CD). By generating an excitation sequence using (BC), (CD), (BE), (CD) and outputting this repeatedly, a composite vector << BCD E >>-9.7 ° is obtained, and address = 3 Positioned at the position.

In addition, when stepping from address = 3 to address = 4, the four excitation groups (CD), (BE) in which the first excitation group (BC) is removed and the last excitation group (BE) is arranged. ), (CD), and (BE) are generated and repeatedly output, thereby obtaining a composite vector << BCD E >> and positioning it at the position of the basic step at address = 4.

In this way, by using the micro-step excitation process of four times from address = 0 to address = 3, the steps of the microstep obtained by dividing each of the ten basic steps of the composite vectors << ABCD >> to << ABC E >> into four. Has realized. Note that the method of subdividing the step angle by changing the ratio of the number of times of excitation between the first excitation group and the second excitation group in this way will be referred to as frequency division hereinafter.

  As another embodiment of the conventional microstep driving method, for example, Japanese Patent Application Laid-Open No. 2004-266974 (Patent Document 2) discloses an excitation phase (U) of a three-phase excitation coil formed in a three-phase stepping motor. There is shown a microstep driving method in which the basic step angle α of the stepping motor is subdivided by performing multiphase excitation by combining the excitation polarities of the phase, V phase, and W phase).

For example, FIG. 6 of Patent Document 2 shows a microstep in which the basic step is divided into 10 by gradually decreasing and gradually increasing the output ratio of the first excitation group (vUw) and the second excitation group (wVu) for each step. The driving method is shown. In FIG. 9 of Patent Document 2, the excitation time of the first excitation group (vUw) is gradually increased or decreased for each step, and the excitation time of the second excitation group (wVu) is gradually decreased or increased for each step. Thus, there is shown a microstep driving method in which excitation waveforms (vUw, UwV, wVu) having different excitation times for each step are generated and a plurality of excitation coils are sequentially excited to divide the basic steps into 100. Note that the method of subdividing the step angle by changing the ratio of the excitation time between the first excitation group and the second excitation group in this way will be referred to as time division hereinafter.
Japanese Patent No. 3725316 JP 2004-266974 A

  In recent years, in a technical field such as an optical measurement device, an optoelectronic device manufacturing device, an organic EL manufacturing device, a device process device, or an organic semiconductor element manufacturing device, precise positioning of the carriage and ultra-low speed driving with low vibration are required. . In addition, as an application of the optical measuring device, parallel light calculation technology, laser stabilization technology, ultrafast spectroscopy technology, ultrafast light control technology, or optical pulse timing synchronization technology, etc., single photon detection technology, Examples include ultrafast optical measurement technology, hologram measurement technology, various surface spectroscopy technologies, electroluminescence measurement technology, mobility measurement technology, or interference measurement technology.

  In each of the above technical fields, stepping motors are frequently used as carriage drive sources due to demands for ease of control, miniaturization of control devices, and cost reductions. Ultra-low speed driving and high resolution driving are also used for stepping motors. There is a strong demand for performance. In addition, cases in which high-resolution stepping motors are incorporated into various devices used in the vicinity of workers working in laboratories and production sites are increasing.

  In order to improve the resolution of the stepping motor using the microstep driving method described in Example 2 of the above-mentioned Patent Document 1, the number of combinations of excitation groups for dividing the basic step angle α (see Patent Document 1). In Example 2, four excitation groups are used.)) Needs to be increased.

  Switching means (Tr1), (Tr3), (Tr5), (Tr7), (Tr9) drains and (Tr2), (Tr4), (Tr6), (Tr6) of the control circuit described in FIG. The power supply voltage is directly applied to the sources of Tr8) and (Tr10). Therefore, the control circuit of Patent Document 1 uses a signal detected by the sensing resistor (R1) to configure a constant current circuit that changes the switching time between when the motor rotor is low speed and when it is high speed. (See FIG. 3 of Patent Document 1).

  Thus, when the stepping motor is driven at a constant current by changing the switching time, an excitation cycle T of a predetermined time is required as a cycle for exciting the excitation coil in order to perform constant current control. If it is assumed that the excitation cycle T = 20 μs, the sequence described in FIG. 3 of Patent Document 1 uses four types of excitation groups. Therefore, the time required for one sequence excitation is four times excitation × 20 μs = 80 μs.

  As shown in FIG. 3 of Patent Document 1, at address 0 and address 4, the excitation of << ABCD >> or << BCDE >> is repeatedly output at a predetermined excitation period T, so that the excitation period T = 20 μs. In other words, the motor rotor emits vibration of 1 / T = 50 kHz. However, since the 50 kHz sound is greatly deviated from the range of 20 Hz to 15 kHz which is a human audible sound region, it cannot be heard by human ears and does not generate noise.

  However, at addresses 1 to 3, the second excitation group << BCDE >> appears at an interval of four excitations x 20 [mu] s = 80 [mu] s with respect to the first excitation group <ABCD>. / (4 times excitation × T) = 12.5 kHz. Since this 12.5 kHz sound is within the range of 20 Hz to 15 kHz, which is considered as a human audible sound range, depending on the person, high-pitched noise can be heard from the stepping motor.

  In the microstep driving method described in FIG. 3 of Patent Document 1, the basic step angle α is divided into four, but in order to achieve ultra-low speed driving and high resolution driving, the resolution is further increased by 10 times. Consider the case where the basic step angle α is divided into 40.

  When the basic step angle α is divided into 40, at addresses 1 to 39, the second excitation group << BCDE >> appears at an interval of 40 times excitation x 20 µs = 800 µs with respect to the first excitation group << ABCD >>. The rotor will oscillate at 1 / (40 times excitation × T) = 1.25 kHz. This sound of 1.25 kHz is within the range of 20 Hz to 15 kHz of the human audible sound region, and is a high-sensitivity frequency band for the human ear, so that annoying high-pitched noise can be heard from the stepping motor. It will be. Therefore, even if a high-resolution microstep can be realized, the noise generated from the stepping motor is too large to be used in an environment where an operator is in the vicinity.

  On the other hand, in the microstep driving method of the stepping motor described in the above-mentioned Patent Document 2, in order to improve the resolution of the stepping motor, the mechanical at the time of gradually decreasing or gradually increasing the first group excitation time and the second group excitation time. The minimum unit excitation time t subject to the restriction is set as short as possible to increase the number of divisions of the basic step angle α. Incidentally, in the embodiment shown in FIG. 9 of Patent Document 2, the unit excitation time t = 0.5 μs and the excitation cycle T = 100 μs are set, and the first group excitation (vUw) is excited. The time is gradually decreased from 50 μs to 0 μs every 0.5 μs in 100 steps, and the second set excitation time for exciting the second excitation group (wVu) is gradually increased from 0 μs to 50 μs every 0.5 μs in 100 steps. .

  The ratio of the output time of the third excitation group (UwV) is set to 50% in all 100 steps, and smooth micro-step driving is performed while reducing the torque ripple generated when switching the polarity of each excitation phase. The problem when the resolution is further reduced by using the micro-step driving method by time division described in Patent Document 2 will be considered.

  If the resolution is further improved by using the time-division micro-step driving method described in Patent Document 2, the minimum excitation time for supplying power to the excitation coil of the stepping motor is less than 0.5 μs. It is necessary to shorten it further. However, since the response time of the switching element is determined in advance by the performance of the element, even if the switching element is instructed to perform a switching operation less than the minimum excitation time, it does not follow the switching time of the excitation current, and is short Excitation control is not possible. Therefore, it is necessary to secure in advance a switching time longer than a predetermined time during which the switching element can respond.

  In such a situation, in order to realize a finer micro step, a finer micro step can be realized by changing the ratio of the number of times of excitation between the first excitation group and the second excitation group. For example, in addition to the microstep driving method described in FIG.

  As shown in FIG. 9 of Patent Document 2, excitation combination (vUw) = 50%, (UwV) = 50%, (wVu) = 0% combined excitation (first excitation set), and excitation set (vUw) By changing the ratio of the number of times of excitation with the combination of excitation (second excitation set) = 49%, (UwV) = 50%, (wVu) = 1%, for example, from 0:10 to 10: 0, Ten micro steps can be realized.

  However, if the number of times division is added in this way, the use may be restricted because annoying noise is emitted from the stepping motor. For example, when the excitation cycle T is 100 μs, the excitation frequency ratio is between 1: 9 and 9: 1, and the excitation phase (wVu) is 10 times excitation × 100 μs = 1000 μs interval with respect to the excitation phase (vUw). The motor rotor will oscillate at 1 kHz. Therefore, annoying high-pitched noise is emitted from the stepping motor. Therefore, even in this case, even if a high-resolution microstep can be realized, it cannot be used in an environment where an operator is nearby due to noise generated by the stepping motor.

  As described above, when exciting the excitation coil of the stepping motor, the resolution can be reduced relatively easily by combining different excitation sets in time series, but the excitation cycle increases as the resolution is reduced. This causes a problem that an audible audible noise is generated from the stepping motor.

  The noise generated from the stepping motor is generated not only when the stepping motor is performing a stepping operation but also when holding the rotation is stopped. Therefore, in the technical field of precision measuring equipment and precision processing equipment that particularly requires high-resolution positioning, there is a strong demand for the appearance of a high-resolution stepping motor drive that operates with low noise.

  The present invention has been made to solve such conventional problems, and a stepping motor driving device that realizes microsteps that reduce generation of annoying noise and dramatically improve the resolution of the stepping motor, It is an object to provide a microstep driving method, precision measuring equipment, and precision processing equipment.

  Furthermore, the present invention can use a conventional electronic circuit configuration without requiring any new addition of a special electronic circuit, and by simply changing a part of the logic circuit, there is less annoying noise and high resolution. It is an object of the present invention to provide a stepping motor driving device, a microstep driving method, a precision measuring device, and a precision processing device that realize a simple microstep.

  That is, the first basic configuration of the present invention is a stepping motor driving apparatus that realizes a microstep for dividing a basic step angle α of an N-phase stepping motor into m fine steps. When a motion command pulse is input, an m-divided counter that counts and outputs the number of steps in fine steps, and a basic step counter that is positioned in the upper digit of the m-divided counter and outputs the number of steps in the basic step And a first excitation set of excitation coils (a combination of one excitation) for positioning the motor rotor of the N-phase stepping motor at the position of one basic step corresponding to the step number of the basic step. ) And the second excitation set (other excitation combinations) for positioning at the position of the next basic step. ) And two excitation groups (combination of excitation) by gradually increasing and decreasing the number of excitations of the two excitation groups (excitation combinations) according to the number of steps in fine steps. The excitation frequency ratio output means for determining and outputting the excitation frequency ratio and the excitation output constituting the first excitation group (one excitation combination) or the second excitation group (other excitation combinations) for each excitation cycle T Excitation period output means for outputting an excitation switching command for switching between the first excitation group (combination of one excitation) and second excitation group (combination of other excitations) while maintaining the determined excitation frequency ratio. On the other hand, the first excitation group (one excitation combination) or the second excitation group (others) is used by using an array of excitation groups (combination of excitations) that are sequentially distributed and output so that they do not appear constantly in a monotonous cycle. The excitation waveform that composes the excitation combination) An excitation waveform output means for outputting every excitation cycle T is provided.

  According to a preferred aspect, the excitation waveform output means has an excitation column K (an excitation column consisting of a predetermined number of excitations) × stage number R (the number of stages in the excitation column K) as an arrangement of the first excitation group and the second excitation group. And an array in which the output order of the second excitation group with respect to the first excitation group at one stage r in the stage number R is always distributed so as to be different from the output order of the stage r-1. It is desirable to use it.

  According to another preferred aspect, the excitation waveform output means includes an excitation column K (an excitation column consisting of a predetermined number of excitations) × stage number R (an excitation column) as an arrangement of the first excitation group and the second excitation group. K), and the output order of the second excitation group with respect to the first excitation group at one stage r in the stage number R is sequentially increased from the front of the excitation row K as the stage r increases. It is desirable that the backward movement pattern for moving backward and the forward movement pattern for sequentially moving forward from the rear of the excitation row K as the stage r increases are dispersed by alternately outputting.

  Furthermore, according to another preferred aspect, the excitation waveform output means includes an excitation column K (an excitation column comprising a predetermined number of excitations) × stage number R (excitation column) as an arrangement of the first excitation group and the second excitation group. K), and the output order of the second excitation group with respect to the first excitation group at one stage r in the stage number R is the excitation sequence K in the first stage (r = 1). Are moved from the center of the excitation row K to the rear, and the forward movement is sequentially moved forward from the center of the excitation row K as the step r increases. It is desirable to include a pattern that is dispersed by alternately outputting the pattern.

  According to another preferred aspect, it is desirable that the excitation waveform output means determines the output order of the second excitation group with respect to the first excitation group based on random number calculation processing.

  Further, the second basic configuration of the present invention is a stepping motor drive that realizes a microstep in which the basic step angle α of the N-phase stepping motor is divided into n steps into fine steps, and further, the fine steps are divided into m steps. In the apparatus, when an N-phase stepping motor rotation command pulse is input, an m-divided counter that counts and outputs the number of steps in a fine step, and a step number in a minute step that is located in the upper digit of the m-divided counter An electrical angle position management means having an n-dividing counter that counts and outputs, and a basic step counter that is positioned in the upper digit of the n-dividing counter and counts and outputs the step number of the basic step, A first excitation set of excitation coils (one excitation) for positioning the motor rotor at the position of one basic step corresponding to the step number of the basic step. Excitation phase combination output means for outputting at least two excitation sets (excitation combinations) of the second excitation set (next excitation combination) for positioning at the position of the next basic step, and N phase In order to position the motor rotor of the stepping motor at the position of one minute step corresponding to the step number of the minute step, it was generated by gradually increasing and decreasing the excitation time of the two excitation groups (excitation combinations) mutually. Time combination output means for outputting a combination of at least two times of a combination of one time and another time combination for positioning at the position of another minute step, and two excitations according to the number of steps of the fine step One excitation time combination that combines a set (excitation combination) and one time, and another excitation that combines two excitation sets (excitation combinations) and another time combination The excitation frequency ratio output means for determining and outputting the excitation frequency ratio of the combination of the two excitation times by gradually increasing and decreasing the excitation frequency with the magnetic time combination, and one excitation time for each excitation cycle T An excitation cycle output means for outputting an excitation switching command for switching an excitation output that constitutes a combination or another excitation time combination, and a combination of one excitation time while maintaining the determined excitation frequency ratio is another excitation. Excitation that constitutes one excitation time combination or another excitation time combination using an array of excitation time combinations that are output in sequence so that they do not appear constantly in a monotonic cycle with respect to the time combination. The main configuration includes excitation waveform output means for outputting a waveform for each excitation period T.

  According to the present invention having the first and second basic configurations, the step angle of the N-phase stepping motor can be further increased while using a conventional electronic circuit and logic circuit without requiring the addition of a special electronic circuit. Subdivided positioning and ultra-low speed driving can be realized, and the generation of annoying noise during rotational driving and holding can be reduced.

  In addition, when driving a stepping motor at a constant current, a chopper-type constant current control circuit that adjusts the excitation time of the excitation coil is used, and multiple types of excitation phases are monotonous in synchronization with the excitation cycle used for the constant current control. By performing excitation using an array dispersed so as not to appear regularly in a cycle, it is possible to realize a microstep with a simple and compact configuration and less noise generation.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail based on examples shown in the accompanying drawings.

  FIG. 1 is a block diagram showing an internal configuration of a stepping motor driving apparatus 10 having a chopper type constant current control circuit 14 that realizes constant current control for the five-phase stepping motor 1 by adjusting excitation time. is there. FIG. 1 shows a state in which a stepping motor driving apparatus 10 according to the present invention is connected to a 5-phase stepping motor 1 of a Pedagon connection system. In the embodiment shown in the figure, an embodiment is shown in which a Pendagon connection type five-phase stepping motor 1 is connected to perform microstep drive control. However, the present invention is a pentagon connection type stepping motor or a five-phase stepping motor. The present invention is not limited to this stepping motor, but can be applied to a star connection type stepping motor or a three-phase stepping motor. It can also be applied to a direct-acting stepping motor.

  As shown in FIG. 1, a stepping motor driving apparatus 10 according to the present invention is configured to rotate a 5-phase stepping motor 1 such as CWP (Clock Wise Pulse) or CCWP (Counter Clock Wise Pulse) from an external device such as a host computer. An excitation pulse determining means 12 for generating an excitation waveform for exciting each excitation coil 1a to 1e of the five-phase stepping motor 1 by inputting a command pulse, and each excitation based on the excitation waveform generated by the excitation waveform determining means 12 And a power element driving circuit 13 for outputting an excitation command for exciting the coils 1a to 1e.

  Further, the stepping motor driving apparatus 10 bypasses the electromotive force generated by the excitation coils 1a to 1e and the power elements TR1 to TR10 for controlling the excitation current for exciting the excitation coils 1a to 1e based on the excitation waveform. The diodes D1 to D10, the power source PS that supplies power for exciting the exciting coils 1a to 1e, the capacitor C1 that smoothes the voltage of the power source PS, and the exciting coils 1a to 1e flow to perform constant current driving. A current detection resistor 15 for detecting current and a constant current control circuit 14 for adjusting the excitation time TP of the excitation coils 1a to 1e according to the impedance of the excitation coils 1a to 1e are provided.

  Here, the rotation command pulse CWP described above is a command pulse for causing the five-phase stepping motor 1 to rotate forward (clockwise rotation as viewed from the output shaft side of the motor rotor) to a predetermined position, and CCWP is This is a command pulse for reverse rotation (counterclockwise rotation) to a predetermined position.

  The excitation waveform determining means 12 shown in FIG. 1 receives a rotation command pulse of the five-phase stepping motor 1 and uses the input rotation command pulse to determine the step number of the basic step and the fine step (for example, the basic step angle α). Represents the step position for each fine step angle divided by m by the number of times division, hereinafter referred to as the number of times division step), and the electrical angle position management means 12a for counting and outputting the number of steps. The first excitation set for positioning the motor rotor of the five-phase stepping motor 1 at the position of one basic step and the positions of other basic steps according to the number of steps of the basic step counted by 12a Excitation phase combination output means 12b for outputting a combination with the second excitation set, and excitation for switching the excitation constituting the first excitation set or the second excitation set for each excitation cycle T. And an excitation cycle output unit 12c that outputs the replacement command.

  In addition, the excitation waveform determining means 12 gradually increases or decreases the number of times of exciting the first excitation group according to the number of steps in the frequency division step, and gradually decreases or gradually increases the number of times of exciting the second excitation group. The excitation number ratio output means 12d for determining and outputting the excitation number ratio of the first excitation group and the second excitation group, and the first excitation group with respect to the second excitation group while maintaining the determined excitation number ratio Excitation waveform output means 12e for outputting the excitation waveform of the first excitation group or the second excitation group at every excitation period T by using an array of excitation groups that are dispersed and sequentially output so that they do not appear constantly in a monotonous cycle. And. It is possible to integrate the functions of the excitation phase combination output means 12b, the excitation frequency ratio output means 12d, and the excitation waveform output means 12e, and to configure them as a single element. In order to facilitate the explanation of the functions, the configuration is described separately for each function.

Next, an embodiment in which the basic step angle α of the five-phase stepping motor 1 is divided into ten will be described with reference to FIGS. 2 and 3.
As shown in FIG. 2 (a), the excitation coils 1a to 1e of the five-phase stepping motor 1 adopting the pentagon connection method and the direction of the excitation current of the excitation phase ABCDEabcde are defined. The relationship between the excitation phase ABCDEabcde of the motor 1 and the torque vectors VA to Ve is defined.

  As shown in FIG. 2A, the excitation phase A and the excitation phase a are defined according to the direction of the current flowing through the excitation coil 1a. In the same manner, excitation phases BbCcDdEe are respectively defined according to the directions of currents flowing through the excitation coils 1b to 1e. Then, the directions of the torque vectors VA to VE and the torque vectors Va to Ve when the respective excitation phases are excited are defined as shown in FIG. As shown in FIGS. 2 (a) and 2 (b), the current flowing through the exciting coil 1a is in the opposite direction between excitation A and excitation a, and the torque vector is also in the opposite direction between VA and Va.

Next, FIG. 3 shows a combination example of excitation phases for positioning the motor rotor at a predetermined basic step position.
In order to simplify the expression, an exciting current is simultaneously applied to a plurality of exciting coils among the five-phase exciting coils 1a to 1e to excite a combination of exciting phases when performing multi-phase excitation. Called a pair. For example, a state where two phases of excitation phase A and excitation phase B are excited simultaneously is called two-phase excitation, and this is expressed as an excitation group (AB). Further, in order to realize the four-phase excitation, the case where the excitation group (AB) and the excitation group (CD) are excited in a time series with the time shifted is referred to as an excitation group (AB-CD).

  In the embodiment shown in FIG. 3, when the motor rotor of the five-phase stepping motor 1 is stopped at the basic step of step = 0, the four phases of the excitation phase ABCD are excited. However, since these four phases cannot be excited simultaneously using a single power source, four-phase excitation can be performed by exciting the excitation group (BC) and excitation group (AD) in time series. Realize. That is, when the motor rotor is stopped at the basic step of step = 0, the excitation current of the excitation set (BC-AD) is generated and output to the 5-phase stepping motor 1.

  Further, as shown in FIG. 3, when the motor rotor of the five-phase stepping motor 1 is stopped at the basic step of step = 1, an excitation current of the excitation group (CD-BE) is generated and output. In this way, positioning in each basic step can be performed by switching the excitation from step = 0 to step = 9.

  For example, when the basic step angle α of the 5-phase stepping motor is 0.72 °, the excitation phase is switched 10 times in the order of ABCD → BCDE → CDEa → DEab → Eabc → abcd → bcde → cdeA → deAB → eABC. Thus, the motor rotor can be rotated by 7.2 °. Further, when the step of 10 steps (0 to 9) is repeated 50 times, the motor rotor rotates 360 °, that is, exactly one rotation.

Next, FIG. 4 shows another embodiment of a combination of excitation phases for positioning the motor rotor at a predetermined basic step position.
In the embodiment shown in FIG. 4, the excitation set (AB-CD) is excited when the motor rotor is stopped at the basic step of step = 0. Further, when stopping the motor rotor at the basic step of step = 1, the excitation set (BC-DE) is excited. In this way, positioning in each basic step can be performed by switching the excitation from step = 0 to step = 9.

  In the embodiment shown in FIGS. 3 and 4, excitation is performed so that both ends of the excitation coils 1 a to 1 e are always connected to either the positive electrode (+) or the negative electrode (−). Thus, by exciting so that the terminals of the exciting coils 1a to 1e are not always opened, the overshoot of the current when stepping from the previous step to the next step is reduced, and the damping characteristic is improved. Therefore, it is possible to reduce the vibration generated in the motor rotor and the noise.

Next, the processing of each block constituting the excitation waveform determining means 12 shown in FIG. 1 will be described with reference to FIG.
In the embodiment shown in FIG. 5, the electrical angle position management means 12a counts and outputs the number of steps in the basic step every time the rotation command pulse of the five-phase stepping motor 1 is input m times in order from the upper digit. A basic step counter, and an m-divided counter (hereinafter referred to as a number-divided step counter) that counts and outputs the number of steps in a number-of-times-divided step obtained by dividing the basic step angle α by m every time a rotation command pulse is input. It has.

  The number division step counter shown in FIG. 5 counts up the number of steps in the number of division steps every time the rotation command pulse CWP is inputted, and counts down the number of steps in the number of division steps every time the rotation command pulse CCWP is inputted. The value is output to the excitation frequency ratio output means 12d. In addition, it is also possible to separately provide a counter for further subdividing the number division step below the number division step counter.

  The basic step counter corresponds to the upper digit of the number division step counter, and is configured to count up by one when the value of the number division step counter is switched from “9” to “0”. Further, the count division step counter is configured to count down by one when the value is switched from “0” to “9”. The step number of the basic step counted by the basic step counter represents the position of the basic step shown in FIGS. 3 and 4 (step = 0 to 9), and the excitation phase for positioning the motor rotor at the predetermined step position. It is a counter for determining a combination.

  When the step number of the basic step is input from the basic step counter, the excitation phase combination output means 12b includes a first excitation group for positioning the motor rotor of the five-phase stepping motor 1 at the position of one basic step, The combination of excitation phases with the second excitation set for positioning at the basic step position is output. In the case of driving a five-phase stepping motor, the number of combinations of the first excitation group and the second excitation group is twice the number N of phases of the five-phase stepping motor 1 as shown in FIGS. There are 10 types.

  The excitation phase combination output means 12b shown in FIG. 5 shows a combination of excitation phases when the five-phase stepping motor 1 is excited in four phases. When exciting the four phases of the first excitation set, 2 An excitation group (F1-F2) for exciting the phase excitation group F1 and the two-phase excitation group F2 in two steps is output. Further, when exciting the four phases of the second excitation group, an excitation group (F3-F4) for exciting the two-phase excitation group F3 and the two-phase excitation group F4 in two steps is output.

  For example, when the excitation shown in FIG. 3 is performed and the basic step counter outputs “0” as the step number of the basic step (when step = 0), the step number of the basic step is An excitation group (AD-BC) is output as the first excitation group in order to realize a microstep obtained by dividing m between “0” and “1”. In addition, an excitation group (BE-CD) is output as the second excitation group. When the basic step counter outputs “1” as the step number of the basic step (when step = 1), the step number of the basic step is a micro divided by m between “1” and “2”. In order to realize the step, the excitation group (BE-CD) is output as the first excitation group, and the excitation group (Ca-DE) is output as the second excitation group. Thereafter, similarly, the first excitation group and the second excitation group are output according to the number of steps in the basic step.

  As an element for realizing the function of the excitation phase combination output means 12b, a memory such as a ROM can be used. In that case, the electrical angle position management means 12a is configured to function as an address counter of the memory.

  The excitation number ratio output means 12d gradually increases or decreases the number of times of exciting the first excitation group and gradually decreases or gradually increases the number of times of exciting the second excitation group according to the number of steps in the number dividing step. A function for determining and outputting the ratio of the number of times of excitation between the first excitation group and the second excitation group is provided. For example, when the number of divisions in the frequency division step is set to m = 10, the number of times of exciting the first excitation group is gradually decreased from 10 to 1, and the number of times of exciting the second excitation group is set to 0. By gradually increasing up to 9 times, it has a function of changing and outputting the number of excitation times of the first excitation group and the second excitation group from 10: 0 to 1: 9. In the embodiment shown in FIG. 5, since 2-phase excitation is output twice in order to realize 4-phase excitation, the number of excitations is 2 times × m division = 20 times (0P to 19P). .

  According to the embodiment shown in FIG. 5, when the number division step counter outputs “0” as the step number of the number division step, the repetition of F1 and F2 of the first excitation group is performed as the excitation phases 0P to 19P. Assign to and output. As a result, the ratio of the number of excitations between the first excitation group and the second excitation group is set to 10: 0, and the motor rotor can be positioned at the position of the step number “0” of the basic step.

  When the number division step counter outputs “1” as the step number of the number division step, F3 and F4 of the second excitation set are substituted into the excitation phases 0P and 1P and output, and the first excitation set is output. The repetition of F1 and F2 is assigned to 2P to 19P and output. Thereby, the ratio of the number of times of excitation between the first excitation group and the second excitation group is set to 9: 1, and the motor rotor is located at a position obtained by dividing the step number “0” and “1” of the basic step into ten. Can be positioned.

  Similarly, the excitation phases 0P to 19P are determined by gradually increasing or decreasing the number of times of exciting the first excitation group according to the number of steps in the number dividing step, and gradually decreasing or gradually increasing the number of times of exciting the second excitation group. The excitation frequency ratio between the first excitation group and the second excitation group is determined and output.

  The excitation cycle output means 12c is a counter for switching and outputting the excitation phases 0P to 19P determined by the excitation frequency ratio output means 12d for each excitation cycle T. This excitation cycle T is also output to the constant current control circuit 14 in order to synchronize with the PWM timing when performing constant current control.

  In addition, by repeatedly outputting the excitation phases 0P to 19P output by the excitation frequency ratio output means 12d for each excitation cycle T, it is possible to realize a microstep by dividing the basic step angle α into m. However, when the number of steps in the number dividing step is between “1” and “9”, the second excitation group (F3-F4) is divided by the excitation cycle T × division with respect to the first excitation group (F1-F2). It appears every several m × the number of excitation times 2. For example, when the excitation cycle T = 20 μs and the number of divisions m = 10, T × m × 2 = 400 μs, and a noise of 2.5 kHz is generated.

  Therefore, in the present invention, while maintaining the excitation frequency ratio between the first excitation group and the second excitation group, the first excitation group is dispersed so as not to appear constantly with a monotonic cycle with respect to the second excitation group. It is configured to sequentially excite. For example, as the arrangement of the first excitation group and the second excitation group, an arrangement divided into excitation column K (excitation column consisting of a predetermined number of excitations) × stage number R (number of stages of excitation column K) is used. An arrangement in which the first excitation group and the second excitation group are always dispersed so that the output order of the second excitation group with respect to the first excitation group in one stage r is different from the output order of the stage r-1. Will be described with reference to FIG.

FIG. 6 shows the arrangement of the excitation waveform output means that generally represents the relationship between the excitation cycle T and the output order of the excitation groups using 0P to 19P when the number of steps in the number dividing step is “1”. It is a column table.
In the embodiment shown in FIG. 6, the excitation phases 0P to 19P are not monotonously repeated at each stage r, but are sequentially outputted from 0P to 19P during the excitation cycle = 0 to 19 (stage r = 0). In the excitation cycle = 20 to 39 (stage r = 1), 2P to 19P and 0P and 1P are sequentially output. In the excitation period = 40 to 59 (stage r = 2), 18P, 19P, In addition, the excitation cycle = 0 to 359 is configured with the number of stages R = 18 so that 0P to 17P are continuously output. In the embodiment shown in FIG. 6, the excitation cycle T = 20 μs and the excitation row K = 20 times of excitation.

  As shown in FIG. 6, as the arrangement of the first excitation group and the second excitation group, an array divided into excitation column K (excitation column consisting of a predetermined number of excitations) × stage number R (number of excitation column K stages) is used. And a rearward movement pattern in which the output order of the second excitation group with respect to the first excitation group in one stage r in the stage number R is sequentially moved from the front to the rear of the excitation row K as the stage r increases, By alternately outputting a forward movement pattern that sequentially moves from the rear to the front of the excitation row K as r increases, the appearance of the second excitation set with respect to the first excitation set can be dispersed.

  For example, between the stage r = 0 and the stage r = 1, the excitation interval of the excitation group (0P-1P) is 38 times × 20 μs = 760 μs, which is 1.31 kHz in terms of frequency. Further, between the stage r = 1 stage and the stage r = 2, the excitation interval of the excitation group (0P-1P) is 4 times × 20 μs = 80 μs, which is 12.5 kHz in terms of frequency. Similarly, since the appearance intervals of the second excitation group with respect to the first excitation group are dispersed, it is possible to prevent the generation of steady sound. Therefore, it is possible to provide a stepping motor driving device with low noise and high resolution.

  A memory such as a ROM can be used as an element for realizing the function of the excitation waveform output means 12e shown in FIG. Further, the excitation phase combination output means 12b and the excitation frequency ratio output means 12d may be combined into a single memory.

FIG. 7 shows an array table showing the relationship between the excitation cycle T and the output order of the excitation groups when the number of steps in the number dividing step is “1”.
7 shows that the excitation set (BE-CD) is assigned to 0P and 1P shown in FIG. 6, the excitation set (AD-BC) is assigned to 2P to 19P, and the excitation cycle T and the output order of the excitation sets. It is the chart showing the relationship. As shown in FIG. 7, the output sequence of the second excitation group (BE-CD) with respect to the first excitation group (AD-BC) in one stage r in the stage number R is sequentially increased as the stage r increases. By alternately outputting a backward movement pattern for moving from the front of K to the rear and a forward movement pattern for sequentially moving from the rear of the excitation row K to the front as the level r increases, a predetermined excitation frequency ratio (9 1), the first excitation group can be dispersed and outputted so as not to appear steadily in a monotonic cycle with respect to the second excitation group.

Next, the operation of the constant current drive control circuit 14 and the excitation waveform output by the excitation waveform output means 12e will be described with reference to FIG.
FIG. 8 is a timing chart showing in time series the relationship between the excitation cycle T, the output order of the excitation groups, and the excitation output. The operation of the constant current drive control circuit 14 and the excitation waveform output means 12e output it. It is a chart explaining the excitation output to be performed.

  As shown in FIG. 7, when the number of steps in the number dividing step is “1”, excitation groups (BE), (CD), (AD), (BC ), (AD), (BC)... Since the impedance of the excitation coils 1a to 1e of the five-phase stepping motor 1 increases according to the rotation speed of the motor rotor, if the excitation coils 1a to 1e are always excited with a constant excitation time, Torque will decrease. Therefore, the excitation waveform output means 12e shortens the excitation time of the excitation coils 1a to 1e when the motor rotor is stopped (during holding) or rotates at a low speed, and the motor rotor operates at a high speed. In the case of rotating at a speed of 1, it is necessary to lengthen the excitation time and to control the current applied to the excitation coils 1a to 1e to be constant.

  As shown in FIG. 8, the excitation waveform output means 12e receives a predetermined excitation set (BE), (CD), (AD), (BC), (AD), BC). Must be output. At this time, the information on the excitation period T is also transmitted to the constant current control circuit 14 to generate a synchronized sawtooth triangular wave. Then, in order to obtain a constant excitation current, an error signal between the reference current value and the detection current generated at both ends of the current detection resistor 15 (see FIG. 1) is generated and compared with the level of the triangular wave. Only when the relationship of error signal ≧ triangular wave is established, the gate is opened to excite the exciting coil.

  With this configuration, when the current flowing through the current detection resistor 15 shown in FIG. 1 decreases, the level of the error signal increases, and the excitation output time becomes longer. Then, the current flowing through the exciting coils 1a to 1e is smoothed by the inductance of the exciting coils 1a to 1e, and as a result, it is possible to perform control in which the current flowing through the exciting coils 1a to 1e is increased. Further, when the current flowing through the current detection resistor 15 increases, the level of the error signal decreases, so that the excitation output time is shortened, and as a result, control is performed to reduce the current flowing through the excitation coils 1a to 1e. It can be carried out.

  In this way, by implementing a constant current control circuit using a chopper circuit, both constant current control and microstep excitation output by frequency division can be easily performed without requiring the addition of a special electronic circuit. Can be performed simultaneously with a simple circuit configuration. Even when the exciting coils 1a to 1e are not excited, the terminals of the exciting coils 1a to 1e are always connected to either the positive electrode or the negative electrode so as not to be in a high impedance state. By doing so, it becomes possible to reduce the overshoot of the current when the excitation output is switched and improve the damping characteristic, and it is possible to reduce vibration and noise.

  By using a chopper method that synchronizes PWM constant current control and excitation group switching in this way, a small stepping using a conventional electronic circuit configuration is possible without the need to add a special electronic circuit. By using the motor drive device, it is possible to realize a high-resolution microstep with less noise, and it is possible to meet the demand for miniaturization of the stepping motor drive device.

Next, the relationship between the high resolution of the microstep and the generation of noise will be described.
As shown in the excitation frequency ratio output means 12d in FIG. 5, when the number of frequency divisions is increased to increase the resolution of the microstep, the number of excitations (0P to 19P) for synthesizing a predetermined excitation ratio is increased. I have to let it. As a result, since the synthesis cycle of the number of excitations is extended, there is a problem that an audible audible noise is generated particularly when the motor is stopped (holding). If the stepping motor is relatively large, since the inductance and rotor inertia of the exciting coils 1a to 1e are large, the amplitude due to the ripple of the exciting current is reduced, and the audible sound is small and not bothered. In stepping motors that tend to be small and the inductances of the exciting coils 1a to 1e are small, the audible sound produced by the stepping motors becomes annoying and is becoming a problem.

  On the other hand, even when the motor rotor emits sound, the volume felt by the person and the discomfort given to the person differ depending on the frequency and continuity of the sound.

  For example, the loudness that humans feel is the magnitude of subjective sounds that humans feel and is not uniform across the audible sound frequency range. That is, even when a sound having the same sound pressure level enters the ear, the sense of magnitude differs depending on the frequency and continuity of the sound. For example, as a first phenomenon that affects how the loudness of sound is affected, in the case of a stationary sound, there is an influence of the frequency characteristic of the ear that sensitivity is good at 2 KHz to 4 KHz and sensitivity is low at low frequencies. To do.

  Further, as a second phenomenon, a spectral masking phenomenon occurs in which, when a sound of a certain frequency is heard, if a sound of another frequency is heard, the other is erased by one sound and cannot be heard.

  In addition, as a third phenomenon, a temporal masking phenomenon occurs in which when a certain sound is stopped immediately and another sound is shortly played, the subsequent sound is erased by the previous sound and cannot be heard.

  Therefore, in the present invention, a short time outside the audible sound is set as the excitation period T, and the first excitation set is monotonous with respect to the second excitation set while maintaining the excitation frequency ratio when the number of times is divided. The excitation waveform of the first excitation group or the second excitation group is output every excitation period T by using an array of excitation groups that are dispersed and sequentially output so that they do not appear regularly at a certain period. In this way, the frequency of the generated sound is constantly changed, and the effect of temporal masking is used so that unpleasant audible sound does not remain in the ear.

Next, another embodiment of the excitation waveform output by the excitation waveform output means 12e will be described.
FIGS. 9 to 12 show an arrangement of the first excitation set and the second excitation set that the excitation waveform output means 12e outputs while maintaining the excitation frequency ratio according to the number of steps in the frequency division step at each stage r. An arrangement table divided into excitation row K = 80 times excitation × number of stages R = 78 is shown. Further, in this arrangement table, in one stage r in the stage number R, the output order of the second excitation group with respect to the first excitation group is sequentially moved backward from the front of the excitation row K as the stage r increases. An example of a distributed arrangement is shown by alternately outputting a pattern and a forward movement pattern that sequentially moves forward from the back of the excitation row K as the stage r increases.

  9 to 12 show an example of excitation number K = 80 times excitation. In order to express the column direction in a compressed manner, the two excitation groups constituting the first excitation group or the second excitation group are shown. The order of outputting the excitation groups (for example, “0” and “1”, “2” and “3”...) Is represented by one column.

  9 to 12, blank columns indicate the timing for outputting the excitation waveform of the first excitation set, and columns with “0” indicate the timing for outputting the excitation waveform of the second excitation set. . FIG. 9 shows the output order of the excitation groups when the number of steps in the number division step is “1”, and FIG. 10 shows the output of the excitation groups when the number of steps in the number division step is “2”. FIG. 11 shows the output order of the excitation group when the number of steps in the number division step is “3”, and FIG. 12 shows the excitation group when the number of steps in the number division step is “9”. Shows the output order.

  As shown in FIGS. 9 to 12, the first excitation set is dispersed so that it does not appear steadily in a monotonous cycle with respect to the second excitation set. By outputting the excitation waveform constituting the group or the second excitation group for each excitation period T, generation of stationary sound in the audible sound region can be prevented, and harsh noise can be reduced.

  FIG. 13 shows that the excitation waveform output means 12e maintains the excitation frequency ratio according to the number of steps in the frequency division step, and the excitation column K = 40 times excitation × number of stages as the arrangement of the first excitation group and the second excitation group. An array divided into R = 36 is used, and the output order of the second excitation group with respect to the first excitation group at one stage r in the number of stages R is the abbreviation of the excitation row K in the first stage (r = 1). A backward movement pattern that is output from the center order and sequentially moves backward from the center of the excitation row K as the step r increases, and a forward movement pattern that sequentially moves forward from the center of the excitation row K as the step r increases. It is a graph which shows the Example containing the pattern disperse | distributed by outputting alternately.

  FIG. 13 is an example showing the output sequence of the excitation group when the step number of the number dividing step is “1” and the excitation number K = 40 times excitation, and the blank column outputs the excitation waveform of the first excitation group. The column in which “0P” and “1P” are entered indicates the timing for outputting the excitation waveform of the second excitation group.

  As shown in FIG. 13, the output order (0P-1P) of the second excitation set at one stage r in the stage number R is changed from the order of the approximate center of the excitation row K at the first stage (stage r = 1). As the level r increases, the backward movement pattern that sequentially moves backward from the center of the excitation row K and the forward movement pattern that sequentially moves forward from the center of the excitation row K as the level r increases are alternately displayed. By outputting, it is possible to prevent generation of steady sound in the audible sound region and reduce unpleasant noise. In the embodiment shown in FIG. 13, since the excitation cycle T = 13 μs, the number of excitations K = 40 times, and the number of excitation stages R = 36, the total excitation cycle (T × K × R) = 18.7 ms. The frequency is 53.4 Hz. Although this 53.4 Hz sound is within the range of 20 Hz to 15 kHz, which is considered as a human audible sound region, it is difficult to hear as noise because it is a low sound region with low sensitivity in the loudness curve. In the embodiment shown in FIG. 13, the number of excitation stages R = 36. However, by increasing the number of excitation stages R, the entire excitation cycle can be extended.

  FIG. 14 shows that the excitation waveform output means 12e maintains the excitation frequency ratio according to the number of steps in the frequency division step, and the excitation column K = 40 times excitation × number of stages as the arrangement of the first excitation group and the second excitation group. An example in which an array divided into R = 30 is used and the output order of the second excitation group with respect to the first excitation group at one stage r in the stage number R is determined based on random number calculation processing to be distributed. FIG.

  FIG. 14 is an example showing the output sequence of the excitation group when the step number of the number dividing step is “1” and the excitation number K = 40 times excitation, and the blank column outputs the excitation waveform of the first excitation group. The column in which “0P” and “1P” are entered indicates the timing for outputting the excitation waveform of the second excitation group.

  As shown in FIG. 14, by determining the output order (0P-1P) of the second excitation set in stage r based on random number calculation processing, it is possible to prevent generation of steady sounds and reduce annoying noise. it can.

  In the embodiment shown in FIG. 14, since the excitation cycle T = 13 μs, the excitation frequency K = 40 excitations, and the excitation stage number R = 30, the total excitation period (T × K × R) = 15. 6 ms, which is 64.1 Hz in terms of frequency. FIG. 15 shows the result of investigating the relationship between the total excitation period and the noise generation state by changing the number of excitation stages R from 1 to 120 in order to investigate the noise caused by this frequency.

  FIG. 15 shows the result of observing the relationship between the number of excitation stages R and the content of noise felt by humans when the output order of the second excitation group with respect to the first excitation group is dispersed based on random number calculation processing. It is a chart. Note that the random number pattern was observed using the output order of two types of random number patterns, pattern 1 and pattern 2, but the difference in noise due to the difference in random number pattern is that the number of excitation stages is about five. In some cases, it only appeared as a difference in sound quality. The data when the number of excitation stages R = 1 is the data described for comparison because there is no effect of random numbers because the same excitation pattern is repeatedly output every stage.

  As shown in FIG. 15, as the excitation stage number R is increased, annoying high-pitched noise is reduced, and the effect of reducing the noise becomes clear when the excitation stage number R ≧ 10. Further, when the number of excitation stages R ≧ 20, a remarkable effect of reducing noise appears.

  Further, as shown in FIG. 15, by setting the excitation stage number R to be R ≧ 100, even if the excitation period is set to 50 ms or more so that the total excitation period is 20 Hz or less, which is the lower limit of the audible sound region, It turns out that the effect of reducing the audible bass is poor. Therefore, if the number of excitation stages R is about R ≧ 20, it is possible to confirm the effect of reducing treble noise and reducing annoying noise.

  On the other hand, if the excitation stage number R is gradually reduced from 20 stages, since the total excitation period is set to 10 ms or less so as to exceed 100 Hz, the noise of the annoying high-frequency component is reduced as the stage number R decreases. Increases significantly. That is, by setting the number of excitation stages R to 10 or more, the noise reduction effect using the excitation arrangement generated by random numbers appears. More preferably, by setting the number of excitation stages R to 20 or more, treble noise can be significantly reduced.

Next, another embodiment of the constant current control circuit will be described with reference to FIGS.
FIG. 16 is a block diagram showing an internal configuration of a stepping motor drive device 30 including a drive voltage conversion type constant current control circuit 34 that realizes constant current control for the five-phase stepping motor 1 by adjusting the excitation voltage. It is. FIG. 16 shows a state in which a pendagon connection type five-phase stepping motor 1 is connected to the stepping motor driving apparatus 30 according to the present invention. FIG. 17 is a diagram showing the functions of the electrical angle position management means 32a, the excitation phase combination output means 32b, the excitation cycle output means 32c, and the excitation frequency ratio output means 32d.

  In addition, in embodiment shown in FIG. 16, although the embodiment which connects the Pedagon connection type | mold 5-phase stepping motor 1 and performs drive control of a micro step is shown, this invention is a stepping motor of a Pentagon connection type, or The present invention is not limited to a five-phase stepping motor, and can be applied to a star connection type stepping motor, or a three-phase, two-phase stepping motor. It can also be applied to a direct-acting stepping motor.

  As shown in FIG. 16, the stepping motor drive device 30 according to the present invention rotates a 5-phase stepping motor 1 such as CWP (Clock Wise Pulse) or CCWP (Counter Clock Wise Pulse) from an external device such as a host computer. Based on the excitation waveform generated by the excitation waveform determination means 32, the excitation waveform determination means 32 for generating an excitation waveform for exciting the excitation coils 1a to 1e of the five-phase stepping motor 1 by inputting a command pulse. A power element drive circuit 33 that outputs an excitation command for exciting the excitation coils 1a to 1e of the stepping motor 1 and an excitation for exciting the excitation coils 1a to 1e of the five-phase stepping motor 1 based on the excitation waveform. Power elements TR1 to TR10 for controlling current, and excitation coils 1a to Diodes D1 to D10 that bypass the electromotive force generated by 1e and a motor current control circuit 36 that controls a current to be supplied according to the impedance of the exciting coils 1a to 1e are provided.

  Here, the rotation command pulse CWP described above is a command pulse for causing the five-phase stepping motor 1 to normally rotate to a predetermined position, and CCWP is a command pulse for causing the reverse rotation to a predetermined position. The excitation waveform determining means 32 outputs the excitation waveforms of the first excitation group and the second excitation group necessary for driving control of the five-phase stepping motor 1 to the power element driving circuit 33.

(Motor current control circuit 36)
The motor current control circuit 36 includes a power source PS that supplies power for exciting the excitation coils 1a to 1e of the five-phase stepping motor 1, a capacitor C1 that smoothes the voltage of the power source PS, and an excitation for constant current driving. A current detection resistor 35 for detecting the current flowing through the coils 1a to 1e, and a transistor TR11 for adjusting the voltage supplied to the exciting coils 1a to 1e by performing PWM driving that repeatedly supplies and cuts off the voltage in a short time. I have.

  Further, the motor current control circuit 36 controls the transistor TR11 on and off according to the voltage generated at both ends of the current detection resistor 35, so that a predetermined current can be obtained without depending on the impedance change of the exciting coils 1a to 1e. A constant current control circuit 34 that performs supply control, a diode D11 that bypasses the electromotive force generated by the exciting coils 1a to 1e, and a choke that generates an intermittent voltage generated by PWM and generates a smooth motor drive voltage. A coil L1 and a capacitor C2 are provided.

  The constant current control circuit 34 detects the current supplied to the exciting coils 1a to 1e, generates a difference between the detected current and the reference current as an error signal, and has a sawtooth triangular wave level as shown in FIG. Compare with Then, only while the relationship of error signal ≧ triangular wave is established, the transistor TR11 is turned on to adjust the voltage supplied to the exciting coils 1a to 1e. The voltage pulsating due to the on / off of the transistor TR11 is smoothed by the choke coil L1 and the capacitor C2, and supplied to the exciting coils 1a to 1e via the power elements TR1 to TR10.

  By configuring the motor current control circuit 36 in this way, when the current flowing through the current detection resistor 35 decreases, the level of the error signal increases, so the on-time of the transistor TR11 becomes longer. Then, the voltage that has passed through the transistor TR11 is smoothed by the choke coil L1 and the capacitor C2 and becomes a high voltage, which is applied to the excitation coils 1a to 1e, so that the excitation voltage can be controlled to increase. Further, when the current flowing through the current detection resistor 35 increases, the level of the error signal decreases, so that the ON time of the transistor TR11 is shortened and control is performed to decrease the voltage applied to the exciting coils 1a to 1e. Can do.

  Thus, by appropriately adjusting the excitation voltage of the five-phase stepping motor 1 using the motor current control circuit 36, the excitation period T of the first excitation group or the second excitation group output from the excitation waveform determining means 32 is Irrespectively, the excitation current can be stabilized and the five-phase stepping motor 1 can be driven at a constant current.

(Excitation waveform determining means 32)
As shown in FIGS. 16 and 17, the excitation waveform determining means 32 inputs a rotation command pulse of the five-phase stepping motor 1, and uses the input rotation command pulse, the number of basic steps, a minute step ( For example, it represents the step position for each minute step angle obtained by dividing the basic step angle α by n by time division (hereinafter referred to as a time division step) and the number of steps in the number division step. The electrical angle position management means 32a that performs the first step for positioning the motor rotor of the five-phase stepping motor 1 at the position of one basic step according to the number of steps of the basic step counted by the electrical angle position management means 32a. Excitation phase combination output means 32b for outputting a combination of the excitation set and the second excitation set for positioning at the position of another basic step is provided.

  In addition, the excitation waveform determining means 32 is arranged to position the motor rotor of the five-phase stepping motor 1 at the position of one time division step corresponding to the number of steps of the time division step. A combination of one time generated by gradually increasing and gradually decreasing the excitation time of the pair (hereinafter referred to as a first time group. TP1 and TP2 shown in FIG. 17 correspond to the first time group). , Another time combination for exciting the first excitation group and the second excitation group for positioning at the position of another time division step (hereinafter referred to as a second time group. TP3 and TP4 shown in FIG. A time combination output means 32f that outputs a combination of at least two times.

  Further, the excitation waveform determining means 32 includes a combination of one excitation time (hereinafter referred to as a first excitation time group) obtained by combining the first excitation group, the second excitation group, and the first time group, and the first excitation group. An excitation number ratio output means 32d for generating an excitation group and another combination of excitation times (hereinafter referred to as a second excitation time group) obtained by combining the second excitation group and the second time group is provided. The excitation number ratio output means 32d further increases and decreases the number of excitations of the first excitation time group and the second excitation time group according to the number of steps in the number division step, thereby increasing the first excitation time. A function of determining and outputting the excitation frequency ratio between the set and the second excitation time set is provided. Thus, the excitation frequency ratio output means 32d further subdivides the time division step using the frequency division by changing the excitation frequency ratio between the first excitation time group and the second excitation time group. Can do.

  The excitation waveform determination means 32 includes an excitation cycle output means 32c for outputting an excitation switching command for switching the excitation output constituting the first excitation time group and the second excitation time group for each excitation period T, and the number of excitations. While maintaining the ratio of the number of times of excitation determined by the ratio output means 32d, the first excitation time group is dispersed so that the first excitation time group does not appear steadily at a monotonous cycle with respect to the second excitation time group, and the excitation time group is sequentially output. Excitation waveform output means 32e that outputs the excitation waveforms of the first excitation time group or the second excitation time group for each excitation cycle T using the arrangement is provided. The excitation phase combination output means 32b, the excitation frequency ratio output means 32d, the excitation waveform output means 32e, and the time combination output means 32f can be integrated into a single element. In this embodiment, in order to facilitate the explanation of each function, the configuration is described separately for each function.

Next, the processing of each block constituting the excitation waveform determining means 32 shown in FIG. 16 will be described with reference to FIG.
In the embodiment shown in FIG. 17, the electrical angle position managing means 32a counts and outputs the number of steps in the number dividing step when the rotation command pulse of the five-phase stepping motor 1 is input in order from the lower digit. A division step counter, an n-division counter (hereinafter referred to as a time division step counter) that is positioned in the upper digit of the number division step counter and counts and outputs the number of steps in the time division step, and the time division step It is provided with a basic step counter that is located in the upper digit of the counter and counts and outputs the number of steps in the basic step.

  The count division step counter shown in FIG. 17 counts up the number of steps in the number of division step every time the rotation command pulse CWP is input, and counts down the number of steps in the number of division step every time the rotation command pulse CCWP is input. The value is output to the excitation frequency ratio output means 32d.

  By inputting the rotation command pulse CWP, the time division step counter counts up the number of steps in the time division step when the value of the number division step counter switches from “39” to “0”, for example. A value is output to the time combination output means 32f. In addition, when the rotation command pulse CCWP is input, the number of steps in the time division step is counted down when the value of the number division step counter is switched from “39” to “0”, for example, and the value is output as a time combination. Output to means 32f.

  The basic step counter is configured to count up by one when the value of the time division step counter is switched from “99” to “0” and to output the value to the excitation phase combination output means 32b. Further, when the value of the time division step counter is switched from “0” to “99”, it is configured to count down by one and output the value to the excitation phase combination output means 32b. The step number of the basic step counted by the basic step counter represents the position of the basic step shown in FIGS. 3 and 4 (steps = 0 to 9), and an excitation phase for positioning the motor rotor at the position of the predetermined basic step. It is a counter for determining the combination.

  When the step number of the basic step is input from the basic step counter, the excitation phase combination output means 32b receives the first excitation group for positioning the motor rotor of the five-phase stepping motor 1 at the position of one basic step, and the motor rotation. A combination of excitation phases with a second excitation set for positioning the child at the position of another basic step is output. Since the function of the excitation phase combination output means 32b is the same as that of the excitation phase combination output means 12b shown in FIG. 5, detailed description thereof is omitted here.

  The excitation cycle output means 32c is a counter for switching and outputting the excitation phases 0P to 159P constituting the first excitation time group and the second excitation time group determined by the excitation frequency ratio output means 32d for each excitation period T. is there.

  The time combination output means 32f first increases the time of excitation of the first excitation group and the second excitation group and gradually decreases them according to the number of steps in the time division step, thereby forming a first time composed of TP1 and TP2. Generate and output tuples. By exciting the first excitation group and the second excitation group using this first time group, the motor rotor can be positioned at the position of one time division step.

  Further, the time combination output means 32f generates and outputs a second time set composed of TP3 and TP4 for positioning the motor rotor at the position of another time division step. By using two time groups, a first time group for positioning in this one time division step and a second time group for positioning in another time division step, there is a further m between time division steps. The number of times of division can be divided.

The relationship between the number of steps in this time division step and the first time group and the second time group will be described with reference to FIG.
FIG. 18 is a chart showing the relationship between the number of steps in the time division step and the excitation times TP1 to TP4 when the number of divisions in time division is set to 100 divisions. As shown in FIG. 18, when the number of divisions by time division is set to n = 100 divisions, the time combination output means 32f is a first excitation group (positioning at the position of one time division step ( The excitation time TP1 of F1-F2) is gradually decreased every 0.2 μs from 20 μs to 0.2 μs, and the excitation time TP2 of the second excitation group (F3-F4) is decreased every 0.2 μs from 0 μs to 19.8 μs. It has a function of gradually increasing the output.

  At the same time, the time combination output unit 32f sets the excitation time TP3 of the first excitation set (F1-F2) for positioning at the position of another time division step from 19.8 μs to 0 μs every 0.2 μs. And a function of gradually increasing the excitation time TP4 of the second excitation set (F3-F4) from 0.2 μs to 20 μs every 0.2 μs. A memory such as a ROM can be used as an element for realizing the function of the time combination output unit 32f shown in FIG.

  Further, as shown in FIG. 17, the excitation number ratio output means 32d first generates the first excitation group (F1-F2), the second excitation group (F3-F4), and the first time group (TP1-TP2). A combined first excitation time group (F1-TP1, F2-TP1, F3-TP2, F4-TP2) is generated. Similarly, a second excitation time group (F1-TP3, F2-TP3) obtained by combining the first excitation group (F1-F2), the second excitation group (F3-F4), and the second time group (TP3-TP4). F3-TP4, F4-TP4).

  Further, the excitation frequency ratio output means 32d has a first excitation time group (F1-TP1, F2-TP1, F3-TP2, F4-TP2) and a second excitation time group (in accordance with the number of steps in the number division step. F1-TP3, F2-TP3, F3-TP4, F4-TP4) are generated and output.

  For example, if the number of steps in the number division step is 0, the motor rotor is positioned at the position of 1 time division step, so excitation by the first excitation time group is 100% and excitation by the second excitation time group. 0%. In this case, the excitation frequency ratio output means 32d outputs repetition of only the first excitation time group. Specifically, when the number of steps in the number dividing step is 0, the excitation number ratio output means 32d provides the excitation set 0P = F1-TP1, 1P = F2-TP1, 2P = F3-TP2, 3P = F4- TP2, 4P = F1-TP1, 5P = F2-TP1, 6P = F3-TP2, 7P = F4-TP2... Are repeatedly output to the excitation set 159P. Here, in order to simplify the following description, the four excitation groups 0P to 3P are represented as excitation time group 0Q, the excitation groups 4P to 7P are represented as excitation time group 1Q, and thereafter, similarly to excitation groups 156P to 159P. Is expressed using the excitation time group 39Q.

  When the number of steps in the number dividing step is 1, it is necessary to set the excitation frequency ratio between the first excitation time group and the second excitation time group to 39: 1. Accordingly, the excitation frequency ratio output means 32d substitutes and outputs the second excitation time group (0P = F1-TP3, 1P = F2-TP3, 2P = F3-TP4, 3P = F4-TP4) as the excitation time group 0Q. Thereafter, the first excitation time groups (F1-TP1, F2-TP1, F3-TP2, F4-TP2) are assigned to the excitation time groups 1Q to 30Q, respectively, and output.

  As a result, the excitation frequency ratio between the first excitation time group and the second excitation time group is set to 39: 1, and the interval between the step numbers “0” and “1” in the time division step is divided into 40 positions. The motor rotor can be positioned.

  When the number of steps in the frequency division step is 2, the excitation frequency ratio between the first excitation time group and the second excitation time group is set to 38: 2 and output. Thereafter, similarly, the first excitation time group and the second excitation time are gradually increased and gradually decreased with respect to each other in accordance with the number of steps in the number dividing step. Determine the excitation frequency ratio of the set and output. A memory such as a ROM can be used as an element for realizing the function of the excitation frequency ratio output means 32d shown in FIG. Further, the excitation phase combination output means 32b, the time combination output means 32f, and the excitation frequency ratio output means 32d may be constituted by an integrated memory.

Next, the function of the excitation waveform output means 32e shown in FIG. 16 will be described with reference to FIG.
FIG. 19 shows an excitation waveform output means 32e that generally represents the relationship between the excitation cycle T and the output order of the excitation time group using the number of excitation K when the number of steps in the number division step is “1”. It is the arrangement | sequence list of.

  In FIG. 19, since the number of times of excitation K = 4 (the number of excitation groups) × 40 times (the number of excitation time groups) = 160 times is shown, in order to compress and express the column direction, The order in which the four excitation time groups constituting the first excitation time group or the second excitation time group are output (for example, 0P to 3P... 156P to 159P) is expressed as a column of a quarter quantity (0Q... 39Q). ing.

  In FIG. 19, a blank column indicates the timing for outputting the excitation waveform of the first excitation time group, and the column in which “0” is entered indicates the timing for outputting the excitation waveform of the second excitation time group. FIG. 19 shows the output order of the excitation groups when the number of steps in the number division step is “1”, so the number of excitations of the first excitation time group and the second excitation time group in each stage r. The ratio is constant at 39: 1.

  As shown in FIG. 19, the excitation waveform output means 32e maintains the excitation frequency ratio (39: 1) corresponding to the number of steps in the frequency division step at each stage r while outputting the first excitation time group and the second excitation time group. As an array of excitation time groups, an array table divided into excitation row K = 160 times excitation × stage number R = 78 is shown. Further, in this arrangement table, the output order of the second excitation time group with respect to the first excitation time group in one stage r in the stage number R is sequentially moved from the front to the rear of the excitation row K as the stage r increases. An example of a distributed arrangement is shown by alternately outputting a backward movement pattern and a forward movement pattern that sequentially moves forward from the rear of the excitation row K as the stage r increases.

  As shown in FIG. 19, the first excitation time group is distributed in order so that the first excitation time group does not constantly appear in a monotonous cycle with respect to the second excitation time group, and the first excitation time group is sequentially output. By outputting the excitation waveforms constituting the group or the second excitation time group at every excitation period T, generation of stationary sound in the audible sound region can be prevented, and harsh noise can be reduced.

  As an element for realizing the function of the excitation waveform output means 32e shown in FIG. 19, a memory such as a ROM can be used. Further, the excitation phase combination output means 32b, the excitation frequency ratio output means 32d, and the time combination output means 32f may be constituted by an integrated memory.

  In the present invention, while maintaining the excitation frequency ratio between the first excitation time group and the second excitation time group, the first excitation time group does not constantly appear in a monotonic cycle with respect to the second excitation time group. For example, excitation waveforms can be output using an arrangement table similar to the arrangement table shown in FIGS. 10 to 14.

  Next, the relationship between the number of steps in the time division step and the excitation times TP1 and TP2 of the first excitation time group and the excitation times TP3 and TP4 of the second excitation time group will be described with reference to FIG.

  FIG. 20 is a timing chart showing the relationship between the number of steps in the time division step and the excitation waveforms of the excitation groups F1 to F4 when the number of steps in the number division step is “1” and the number of excitation stages r = 1.

  FIG. 20 shows excitation waveforms when the time division steps are “0”, “1”, and “99”. When the time division step number is “0”, the excitation time of the first excitation time group is TP1 = 20 μs, TP2 = 0 μs, and the excitation time of the second excitation time group is TP3 = 19 from FIG. .8 μs, TP4 = 0.2 μs. Therefore, when the number of steps in the number dividing step is “1” and the number of excitation stages is r = 1, the first excitation time group (1Q to 39Q) is excited with the excitation time TP1 = 20 μs and TP2 = 0 μs from FIG. Then, the second excitation time set (0Q) is excited at the excitation time TP3 = 19.8 μs and TP4 = 0.2 μs.

  When the number of steps in the time division step is “1”, the first excitation time group (1Q to 39Q) is excited with the excitation times TP1 = 19.8 μs and TP2 = 0.2 μs from FIG. Two excitation time groups (0Q) are excited at excitation times TP3 = 19.6 μs and 0.4 μs. When the number of steps in the time division step is “99”, the first excitation time group (1Q to 39Q) is excited with the excitation times TP1 = 0.2 μs and TP2 = 19.8 μs from FIG. Two excitation time groups (0Q) are excited with excitation times TP3 = 0 μs and TP4 = 20 μs.

  As described above, the basic step angle α can be divided into n × m = 100 × 40 = 4000 by coexisting time division and frequency division. Furthermore, in the present invention, since the first excitation time group is dispersed and sequentially output so that it does not appear steadily in a monotonic cycle with respect to the second excitation time group, the microstep by dividing the number of times is performed. Even so, harsh noise can be reduced. In the present invention, the excitation coils 1a to 1e can be excited using the arrangement tables shown in FIGS.

  The stepping motor driving device and the microstep driving method according to the present invention are suitable for applications that require quietness in addition to precise positioning or low-speed driving with low vibration. For example, the present invention can be applied to an optical measurement device, an optoelectronic device manufacturing device, an organic EL manufacturing device, a device process device, an organic semiconductor element manufacturing device, or the like.

  Applications of the optical measurement device include parallel light calculation technology, laser stabilization technology, ultrafast spectroscopy technology, ultrafast light control technology, or optical pulse timing synchronization technology, and single photon detection. Examples of such technical fields include technology, ultrafast optical measurement technology, hologram measurement technology, various surface spectroscopy technologies, electroluminescence measurement technology, mobility measurement technology, and interference measurement technology.

  In the above embodiment, the microstep driving method of the present invention is used for driving a rotary stepping motor. However, the present invention can be applied to a direct acting stepping motor.

1 is a block diagram of a stepping motor driving apparatus showing a typical embodiment of the present invention that performs constant current control of a five-phase stepping motor by a chopper method. (A) is a figure which defines the excitation coil 1a-1e of the 5-phase stepping motor 1 which employ | adopted the pentagon connection system, and the direction of the excitation current of excitation phase ABCDEabcde. (B) is a diagram defining the relationship between the excitation phase ABCDEabcde of the five-phase stepping motor 1 and the torque vectors VA to Ve. It is a figure which shows the example of a combination of the excitation phase which positions a motor rotor in the position of a predetermined | prescribed basic step. It is a figure which shows the other Example of the combination of the excitation phase which positions a motor rotor in the position of a predetermined | prescribed basic step. It is a figure which shows the function of the electrical angle position management means 12a, the excitation phase combination output means 12b, the excitation period output means 12c, and the excitation frequency ratio output means 12d which were shown in FIG. It is a graph which shows the example of arrangement | sequence of the excitation waveform output means of this invention which generally represented the relationship between the excitation period T and the output order of an excitation group using 0P-19P. It is a table | surface which shows the example of an arrangement | sequence which shows the relationship between the excitation period T and the output order of an excitation group in case the step number of a frequency | count division | segmentation step is "1". It is a timing chart explaining the operation | movement of the constant current drive control circuit 14 in this invention, and the excitation output which the excitation waveform output means 12e outputs. A backward movement pattern in which the output order of the second excitation group with respect to the first excitation group is sequentially moved from the front to the rear of the excitation row K, and a forward movement pattern in which the excitation row K is sequentially moved from the rear to the front as the level r increases. Is a chart of an array table showing an example of alternately outputting (when the number of steps in the number dividing step is “1”). 10 is a diagram of an array table showing an example in which the number of steps in the number division step is “2” in the output order of the excitation groups shown in FIG. 9. FIG. 10 is a diagram of an array table showing an embodiment in the case where the number of steps in the number dividing step is “3” in the output order of the excitation groups shown in FIG. 9. FIG. 10 is a diagram of an array table showing an example in which the number of steps in the number dividing step is “9” in the output order of the excitation groups shown in FIG. 9. The output order of the second excitation group with respect to the first excitation group is a backward movement pattern that sequentially moves backward from the center of the excitation row K as the step r increases, and forward from the center of the excitation row K sequentially as the step r increases. It is a table | surface of the arrangement | sequence table | surface which shows the Example which outputs alternately the front movement pattern made to move to. It is a table | surface of the arrangement | sequence table which shows the Example which determines the output order of the 2nd excitation group with respect to a 1st excitation group based on random number calculation processing, and distributes and outputs it. It is a graph which shows the result of having observed the relationship between the stage number of excitation R, and the content of the noise which a person feels, when the output order of the 2nd excitation group with respect to a 1st excitation group is distributed based on random number calculation processing. FIG. 6 is a block diagram of a stepping motor driving apparatus showing another embodiment of the present invention in which constant current control is performed on a five-phase stepping motor by adjusting an excitation voltage. It is explanatory drawing which shows the function of the electrical angle position management means, excitation phase combination output means, excitation cycle output means, and excitation frequency ratio output means shown in FIG. It is a chart showing the relationship between the number of steps in the time division step and the excitation times TP1 to TP4 when the division number of the time division is set to 100 divisions. When the number of steps in the number of times division step is “1”, the relationship between the excitation period T and the output order of the excitation time group is an array table that generally represents the number of times of excitation K. 10 is a timing chart showing the relationship between the number of steps in the time division step and the excitation waveforms of the excitation groups F1 to F4 when the number of steps in the number division step is “1” and the number of excitation stages is r = 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 5 phase stepping motor 1a-1e Excitation coil 10 Stepping motor drive device 12 Excitation waveform determination means 13 Power element drive circuit 14, 34 Constant current control circuit 15 Current detection resistance 12a, 32a Electrical angle position management means 12b, 32b Excitation phase combination Output means 12c, 32c Excitation period output means 12d, 32d Excitation frequency ratio output means 12e, 32e Excitation waveform output means 32f Time combination output means 30 Stepping motor drive device 32 Excitation waveform determination means 33 Power element drive circuit 35 Current detection resistor 36 Motor Current control circuit C1, C2 Capacitors D1-D11 Diode L1 Choke coil PS Power supply TR1-TR10 Power element TR11 Transistors VA-VE, Va-Ve Torque vector

Claims (9)

In a stepping motor driving apparatus that realizes a microstep that divides a basic step angle α of an N-phase stepping motor into m fine steps,
When a rotation command pulse of the N-phase stepping motor is input, the m-dividing counter that counts and outputs the number of steps in the fine step, and the number of steps in the basic step that is located at the upper digit of the m-dividing counter An electrical angle position management means having a basic step counter for outputting
The motor rotor of the N-phase stepping motor is positioned at the position of one basic step corresponding to the number of steps of the basic step, and at the position of the other basic step and the combination of one excitation coil. Excitation phase combination output means for outputting at least two excitation combinations with other excitation combinations for:
According to the number of steps in the fine step, the number of excitations of the two excitation combinations is gradually increased and decreased, thereby determining and outputting the excitation number ratio of the two excitation combinations. Means,
Excitation period output means for outputting an excitation switching command for switching the excitation output constituting the combination of the one excitation or another excitation for each excitation period T;
While maintaining the determined excitation frequency ratio, the one excitation combination is dispersed so that it does not constantly appear in a monotonous cycle with respect to the other excitation combinations, and the excitation combinations are sequentially output. Excitation waveform output means for outputting an excitation waveform constituting the combination of excitations 1 or other excitations for each excitation period T;
A stepping motor driving device comprising:   The excitation waveform output means uses, as the array of combinations of the two excitations, an array divided into excitation column K (excitation column consisting of a predetermined number of excitations) × stage number R (number of stages of excitation column K), and The output order of one excitation combination with respect to one excitation combination in one stage r in the number of stages R is an array that is always distributed so as to be different from the output order of the stage r-1. 2. A stepping motor drive device according to 1.   The excitation waveform output means uses, as the array of combinations of the two excitations, an array divided into excitation column K (excitation column consisting of a predetermined number of excitations) × stage number R (number of stages of excitation column K), and A rearward movement pattern in which the output order of another excitation combination with respect to one excitation combination in one stage r in the stage number R is sequentially moved from the front to the rear of the excitation row K as the stage r increases; 2. The stepping motor drive device according to claim 1, wherein the stepping motor drive device is an array in which forward movement patterns for sequentially moving from the rear side to the front side of the excitation row K are distributed by alternately outputting as the value increases.   The excitation waveform output means uses, as the array of combinations of the two excitations, an array divided into excitation column K (excitation column consisting of a predetermined number of excitations) × stage number R (number of stages of excitation column K), and The output order of other excitation combinations with respect to one excitation combination in one stage r in the number of stages R is output from the order of the approximate center of the excitation row K in the first stage (r = 1), and the stage r Are distributed by alternately outputting a backward movement pattern that sequentially moves backward from the center of the excitation row K as the value increases, and a forward movement pattern that sequentially moves forward from the center of the excitation row K as the level r increases. The stepping motor driving apparatus according to claim 1, further comprising a pattern to be generated.   2. The stepping motor driving apparatus according to claim 1, wherein the excitation waveform output means determines the output order of other excitation combinations with respect to one excitation combination based on random number calculation processing. In a stepping motor driving apparatus that realizes a microstep that divides a basic step angle α of an N-phase stepping motor into n steps and divides the minute step into m steps.
When a rotation command pulse of an N-phase stepping motor is input, an m-divided counter that counts and outputs the number of steps in the fine step, and a step number in a minute step that is located in the upper digit of the m-divided counter An electrical angle position management means having an n-divided counter that outputs and a basic step counter that counts and outputs the step number of the basic step that is located in the upper digit of the n-divided counter;
The motor rotor of the N-phase stepping motor is positioned at the position of one basic step corresponding to the number of steps of the basic step, and at the position of the other basic step and the combination of one excitation coil. Excitation phase combination output means for outputting at least two excitation combinations with other excitation combinations for:
In order to position the motor rotor of the N-phase stepping motor at the position of one minute step corresponding to the number of steps of the minute step, the excitation time of the combination of the two excitations is gradually increased and decreased mutually. Time combination output means for outputting a combination of at least two times, one generated time combination and another time combination for positioning at the position of another minute step;
Depending on the number of steps in the fine step, another combination of one excitation time that combines the two excitation combinations and one time, and another combination of the two excitation combinations and another time combination. Excitation number ratio output means for determining and outputting the excitation frequency ratio of the two excitation time combinations by gradually increasing and decreasing the excitation frequency with the combination of excitation times;
An excitation cycle output means for outputting an excitation switching command for switching the output of excitation constituting the combination of the one excitation time or the combination of other excitation times for each excitation cycle T;
A combination of excitation times that are sequentially output while being dispersed so that the combination of the excitation times of 1 does not appear regularly in a monotonous cycle with respect to the combinations of other excitation times while maintaining the determined excitation frequency ratio Excitation waveform output means for outputting the excitation waveform constituting the combination of the one excitation time or the combination of the other excitation times at every excitation period T using the arrangement of
A stepping motor driving device comprising:   A precision measuring instrument obtained by driving an N-phase stepping motor using the stepping motor driving apparatus according to any one of claims 1 to 6.   A precision processing apparatus, wherein an N-phase stepping motor is driven using the stepping motor driving device according to any one of claims 1 to 6.   A micro-step driving method of an N-phase stepping motor using the stepping motor driving device according to any one of claims 1 to 6.

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