JP6425305B2 - Driving device for stepping motor and driving method of stepping motor - Google Patents

Description

  The present invention relates to a drive device and a drive method for stepping driving a stepping motor by switching the excitation phase of an HB type 5-phase stepping motor in which five excitation coils are annularly connected.

  Generally, when driving a motor rotor of a five-phase stepping motor having five excitation coils, a command pulse is input from the outside to a driving device of the stepping motor, and the driving device counts the input command pulses. At the same time, control is performed to rotate the motor rotor by an angle proportional to the total number of command pulses by switching the excitation of the excitation coil of the 5-phase stepping motor according to the count value.

  In addition, for example, in order to refine the positioning resolution of the motor rotor of a 5-phase stepping motor, half-step drive in which a basic step angle determined from the mechanical structure of the 5-phase stepping motor is divided into halves and driven The micro step drive which divides and drives an angle | corner into a still finer angle is performed.

  For example, Japanese Patent No. 5327666 (hereinafter referred to as Patent Document 1) discloses a driving device of a stepping motor that performs micro-step driving in which a basic step angle of an N-phase stepping motor is divided into m.

  The driving device for a stepping motor according to Patent Document 1 includes an m-divided counter that counts and outputs the number of steps in fine steps (micro steps) and a basic step counter that counts and outputs the number of steps in basic steps (full steps). The excitation ratio of the two excitation sets in the excitation combination according to the value of the m phase counter and the value of the basic step counter, and the excitation phase combination output means for outputting the excitation combination of the two excitation groups Excitation period determining means for determining the unit excitation cycle output unit for outputting a unit excitation switching command each time a predetermined unit excitation cycle T is counted, and a combination excitation cycle TC configured by an integer multiple of the unit excitation cycle T Combination excitation cycle output means for outputting a combination excitation switching command each time the value is counted, and each time a combination excitation switching command is output, or A unit using excitation ratio storage means for storing a new excitation ratio each time the value of the basic step counter is updated in addition to each time an excitation switching command is output, and an excitation ratio stored in the excitation ratio storage means An excitation waveform output unit that switches the excitation every time the excitation switching command is output and sequentially outputs through the drive element is provided, and all the terminals in the excitation coil of the two-phase excitation constituting the excitation set are motors It is characterized in that the excitation is connected to either the positive electrode or the negative electrode of the drive power supply.

  The driving device of the stepping motor according to Patent Document 1 will be briefly described. In the driving device of Patent Document 1, a plurality of excitation sequences respectively corresponding to full step positions and micro step positions are set. In this case, each excitation sequence corresponding to the full step position is constituted by one excitation group combining two two-phase excitation patterns, and excitations of these two-phase excitation patterns are mutually shifted in time. Thus, the synthesized four-phase excitation is realized. Further, each excitation sequence corresponding to the microstep position is configured by combining two excitation sets having two two-phase excitation patterns at an excitation ratio corresponding to the microstep position.

  Furthermore, in the drive device of Patent Document 1, each time the command pulse is input, the address corresponding to each step position is counted up or down and managed, and the excitation sequence corresponding to the address is selected to excite the same. The excitation pattern of the sequence is switched for each unit excitation cycle T generated independently of the command sequence, and the excitation coil is excited in order at a predetermined cycle (excitation cycle TC). Further, at this time, each time the excitation cycle TC is repeated, the address of the managed step position is confirmed, and the corresponding excitation sequence is selected (updated).

  Furthermore, in Patent Document 1, not only the address of the step position is selected every excitation cycle TC as described above, but every time the address of the full step position is counted, the excitation sequence corresponding to the full step position is selected. Then, the excitation according to the two-phase excitation pattern is performed in a predetermined cycle (excitation cycle TC).

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

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

Patent No. 5327666

Since the stepping motor has excellent controllability, it has been widely used in industrial apparatuses in various fields such as precision machines and measuring devices.
On the other hand, with recent technological development, stepping motors that can obtain the required torque even at high rotational speeds, and stepping motors that can obtain larger torques in the low rotational speed and super low rotational speed areas are newly developed. It has been sold. Further, for example, by using a stepping motor having a larger rated current, it is possible to realize the torque increase and speedup of the stepping motor.

  For this reason, in the industrial apparatus in which the stepping motor is already assembled and operating, the efficiency of the industrial apparatus is improved and the productivity is improved by increasing the torque of the stepping motor or increasing the speed as described above. It is possible to

  In the conventional stepping motor, in particular, although torque in a low speed region and a medium speed region is often sufficiently secured in a high speed region where the motor rotation speed is high, the motor coil (excitation coil) Due to the increase in the impedance of the motor coil, it becomes difficult for the current to flow through the motor coil, and at a certain rotation speed or more, a predetermined current does not flow through the exciting coil, resulting in current saturation. As described above, since sufficient torque can not be obtained when the stepping motor is in the current saturation state, it has been difficult to increase the speed of the device without replacing the stepping motor.

  As described above, although using a stepping motor having a larger rated current makes it easier to secure torque in a high speed region, heat generation of the stepping motor and heat generation of its driving device (driver) are also large with the increase of the current. Therefore, depending on the device, it may not be possible to use a stepping motor having a large rated current.

  Also, one industrial device uses a large number of stepping motors and a large number of drive devices and control devices (controllers) for driving the stepping motors. In many cases, a single device is used. A stepping motor with 100 or more axes may be used.

  Therefore, in order to replace the stepping motor assembled in one device with a new stepping motor or a stepping motor with a large rated current for increasing torque and speed, many stepping motors are simultaneously replaced, It is also necessary to replace the dedicated drive unit and control unit. Furthermore, the design of the power supply and the design of the wiring also need to be reviewed, which is expensive.

  In addition, many industrial devices that use stepping motors have been certified as safety standards from a predetermined certification organization, so stepping motors that become important parts of the device parts and their drive devices There was also a problem that it could not be replaced easily. For this reason, it has been strongly demanded by the user to increase the torque in the high speed region to improve the speed and productivity of the device without replacing the stepping motor.

  The present invention has been made in view of the above-described conventional problems, and its object can be applied without rewriting the stepping motor by rewriting the internal logic circuit, and in the low speed region or in the middle An object of the present invention is to provide a stepping motor drive device capable of increasing torque in a high speed region while securing torque in a high speed region, and a driving method of the stepping motor.

  In order to achieve the above object, the stepping motor drive provided by the present invention switches the excitation phase of an HB type 5-phase stepping motor in which five excitation coils are annularly connected by inputting a command pulse, A driving device for a stepping motor for stepping driving the stepping motor, a motor rotation management unit that counts the command pulse and manages an electrical angle position and a rotation speed of the stepping motor, and excitation having a plurality of excitation patterns An excitation pattern storage unit for storing a sequence, an excitation pattern selection unit for selecting the corresponding excitation sequence from the excitation pattern storage unit based on the electrical angle position and rotation speed managed by the motor rotation management unit, and a plurality of switchings The excitation sequence selected by the excitation pattern selection unit. And a switching unit for switching the excitation phase of the stepping motor by controlling ON / OFF of each switching element in accordance with the excitation pattern of the motor. A plurality of high-speed excitation sequences, which are set by combining an excitation pattern of two-phase excitation having a combined impedance lower than that of the four-phase excitation and other excitation patterns of multiphase excitation, are stored. The electric angle is selected when the rotational speed controlled by the motor rotation management unit is in a high speed region where the rotational speed is equal to or higher than a predetermined high speed determination speed higher than the current saturation rotational speed at which the current flowing in the stepping motor is saturated. Pre-set to select the high speed excitation sequence corresponding to the position It is an most important characterized in that is.

  In the stepping motor drive device according to the present invention, in particular, the excitation pattern storage unit stores a plurality of medium speed excitation sequences having only four-phase excitation excitation patterns, and the excitation pattern selection unit is configured to The medium-speed excitation sequence corresponding to the electrical angle position is selected in a medium-speed range in which the speed is a predetermined medium-speed determination speed or more slower than the current saturation rotation speed and less than the high-speed determination speed. It is preferable to set in advance.

  In the driving apparatus for a stepping motor according to the present invention, the excitation sequence for high speed is set by combining the excitation pattern of the two-phase excitation with the excitation pattern of the four-phase excitation and / or the excitation pattern of the three-phase excitation. Is preferred.

  In the driving device for a stepping motor according to the present invention, a high speed sequence group having a plurality of high speed excitation sequences corresponding to each rotational speed range of the high speed region is stored in the excitation pattern storage unit. Preferably, the selection unit is preset to select the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotational speed.

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

  Furthermore, the stepping motor drive device according to the present invention has a current saturation determination unit that determines that the current flowing through the stepping motor is saturated and detects the current saturation rotation speed, and the excitation pattern storage unit includes A plurality of the high speed sequence groups corresponding to the speed range of the current saturation rotational speed are stored in advance, and the excitation pattern selection unit corresponds to the current saturation rotation speed detected from the plurality of high speed sequence groups Preferably, it is preset to select one of the high speed sequence groups.

  Next, according to the driving method of a stepping motor provided by the present invention, an excitation phase of an HB type 5-phase stepping motor in which five excitation coils are annularly connected is switched by input of a command pulse to step the stepping motor. A driving method of a stepping motor to be driven, which is set by combining an excitation pattern of two-phase excitation and an excitation pattern of other multi-phase excitations in which the combined impedance of the excitation phase is lower than that of four-phase excitation. A plurality of high-speed excitation sequences are stored in advance in an excitation pattern storage unit, and the rotation speed managed by the motor rotation management unit is faster than a current saturation rotation speed at which the current flowing through the stepping motor is saturated. The high speed corresponding to the electrical angle position in a high speed region where the predetermined high speed determination speed is reached or higher It is an most important feature that it comprises selecting the excitation sequence.

  In particular, in the stepping motor drive method according to the present invention, a plurality of medium-speed excitation sequences having only four-phase excitation excitation patterns are stored in advance in the excitation pattern storage unit; Selecting the medium-speed excitation sequence corresponding to the electrical angle position in a medium-speed range in which the medium speed determination speed is lower than the high-speed determination speed at a predetermined medium-speed determination speed that is lower than the current saturation rotational speed; It is preferable to contain.

  In the method of driving a stepping motor according to the present invention, the excitation pattern storage unit may store in advance the high speed sequence group having the plurality of high speed excitation sequences corresponding to the respective rotational speed ranges of the high speed region. And selecting the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotational speed in the high-speed region.

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

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

  In particular, the excitation pattern selection unit according to the present invention selects from the excitation pattern storage unit a medium speed excitation sequence having only a four phase excitation excitation pattern in the medium speed region, and the current is saturated in the four phase excitation. In the high speed region which is higher than the high speed rotational speed faster than the current saturation rotational speed, the excitation pattern memory for high speed in which the excitation pattern of two phase excitation is mixed with the excitation pattern of four phase excitation etc. It is preset to select from the department.

  According to such a driving device for a stepping motor of the present invention, when the rotational speed of the stepping motor is in a low speed region, for example, a low speed excitation sequence for performing microstep driving as in the prior art and other low speed excitation sequences are used. Thus, the stepping motor can be smoothly rotated and an appropriate torque can be stably secured.

  When the rotational speed is in the middle speed range, full step drive is performed using an excitation pattern of four-phase excitation which excites four excitation coils simultaneously. Thus, the stepping motor can be rotated more smoothly in the medium speed region, and the combined torque by the four-phase excitation can be appropriately secured.

  Furthermore, when the rotational speed is in the high speed region, full step drive is performed in accordance with the high speed excitation sequence having at least one excitation pattern of two-phase excitation. For example, when an excitation pattern of two-phase excitation is selected to excite a five-phase stepping motor, for example, a predetermined current set is higher than when excitation is performed with an excitation pattern of four-phase excitation such as a medium speed region. Although the combined torque when properly flowing is small, the combined impedance of the entire excited coils can be lowered (ie, the combined impedance when two of the five excitation coils are excited is This is lower than the combined impedance when four of the five excitation coils are excited).

  For this reason, the rotational speed of the motor is increased and the impedance of the excitation coil is increased, so that the combined impedance is low in a high speed region higher than the rotational speed (current saturation rotational speed) at which current is saturated in four phase excitation. By utilizing the excitation pattern of the excitation, the current flows more easily to the stepping motor than the excitation pattern of the four-phase excitation in which the current is saturated, and as a result, a larger combined torque can be obtained in a high speed region.

  Therefore, such an excitation pattern of two-phase excitation is mixed with, for example, an excitation pattern of four-phase excitation to set the high-speed excitation sequence, and the high-speed excitation sequence is selected in the high-speed region. The reduction rate of the torque in the high speed region can be made smaller than that of the conventional one without increasing the rated current of the motor and the heat generation, so that the torque in the high speed region can be effectively extended.

  Moreover, since the drive device of the present invention can be applied to the conventional stepping motor by rewriting the logic circuit (program) in the conventional drive device, the drive device is already assembled in various devices. There is no need to replace the stepping motor. Therefore, it is possible to realize the torque increase in the high speed region as described above of the stepping motor and the speedup by the torque increase without causing a large cost burden.

  In such a drive device of the present invention, the excitation sequence for high speed is set by combining the excitation pattern of four-phase excitation and / or the excitation pattern of three-phase excitation with the excitation pattern of two-phase excitation. Thus, for example, by appropriately combining the excitation pattern of two-phase excitation with the excitation pattern of four-phase excitation and / or the excitation pattern of three-phase excitation, in consideration of, for example, the rotation characteristics and vibration characteristics of the stepping motor, The vibration of the stepping motor can be suppressed to perform high-speed rotation, and the step-out phenomenon can be effectively prevented.

  Further, in the stepping motor drive device according to the present invention, the excitation pattern storage unit stores a high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotational speed range in the high-speed region. It is preset to select a corresponding high speed excitation sequence from the high speed sequence group based on the rotational speed.

  Thus, in each rotational speed range in the high speed region, the stepping motor can be step-driven by selecting the high-speed excitation sequence appropriately corresponding to the rotational speed, so that the stepping motor can smoothly go to higher rotational speeds. While being able to rotate, it is possible to prevent the step-out phenomenon more effectively.

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

  In the present invention, the high-speed excitation sequence selected when the rotational speed is equal to or higher than a predetermined ultra-high-speed determination speed higher than the high-speed determination speed includes an excitation pattern forming a torque vector corresponding to one full step position; The excitation pattern forming the torque vector corresponding to the next full step position and / or the excitation pattern forming the torque vector corresponding to the half step position between both full step positions. This makes it easy to rotate the motor to the next full step position when performing full step driving in a high speed region, and effectively prevents the motor rotation from following the switching of excitation by the input of the command pulse. It can prevent.

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

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

  As a result, when the rotation speed of the stepping motor is in the low speed region, the stepping motor can be smoothly rotated and an appropriate torque is stabilized, for example, by using the low-speed excitation sequence for performing microstep drive as in the prior art. Can be secured. When the rotational speed is in the medium speed range, full stepping drive is performed using the excitation pattern of four-phase excitation that simultaneously excites four excitation coils, thereby smoothly rotating the stepping motor and combining by four-phase excitation Torque can be secured appropriately.

  Furthermore, when the rotational speed is in a high speed region, full step drive is performed according to a high speed excitation sequence having at least one two phase excitation excitation pattern having a combined impedance lower than four phase excitation and the other multiphase excitation excitation patterns. By doing this, the current flows more easily to the stepping motor than the excitation pattern of the four-phase excitation in which the current saturates, and as a result, a larger combined torque can be obtained. Therefore, the reduction rate of the stepping motor torque can be made smaller in the high speed region than in the conventional case, and the torque in the high speed region can be effectively extended.

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

  Thus, in each rotational speed range in the high speed region, the stepping motor can be step driven by selecting the high speed excitation sequence appropriately corresponding to the respective rotational speed range, so that the stepping motor can be driven to a higher rotational speed. While being able to rotate smoothly at high speed, it is possible to prevent the step-out phenomenon more effectively.

  In this case, a plurality of high speed sequence groups corresponding to the speed range of the current saturation rotational speed are stored in advance in the excitation pattern storage unit, and it is determined that the current flowing to the stepping motor is saturated to determine the current saturation rotation speed. A high speed sequence group corresponding to the detected high speed sequence group is selected based on the detected current saturation rotation speed. As a result, the motor characteristics based on the inductance of the stepping motor can be determined according to the magnitude of the current saturation rotational speed, and the optimum high-speed sequence group suitable for the stepping motor can be selected. Can.

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

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

  The driving device 10 for the stepping motor 1 according to the first embodiment shown in FIG. 1 is connected to an HB type 5-phase stepping motor 1 of a pendagon connection method, and for example, the stepping motor 1 with a rated current of 1.4 A / phase. It is a driver that makes it step drive. While the command pulse CWP (ClockWise Pulse) or the command pulse CCWP (Counter Clock Wise Pulse) is input from an external device such as a controller to this drive device 10, the resolution when performing microstep driving (number of divisions of full step angle) The resolution command to determine is input.

  Here, the command pulse CWP is a command pulse for causing the motor rotor (rotor) of the 5-phase stepping motor 1 to rotate clockwise to a predetermined rotation position. The command pulse CCWP is a command pulse for reversely rotating counterclockwise to a predetermined rotational position.

Next, the excitation at the time of dividing one electrical angle (7.2 °) of the 5-phase stepping motor 1 into 10 at the full step (basic step) will be described with reference to FIGS.
First, as shown in FIG. 2 (a), the excitation coils of a five-phase stepping motor 1 adopting a pentagon connection system are designated 1a, 1b, 1c, 1d and 1e, and the respective excitation coils 1a, 1b, 1c, 1d and 1e The excitation current flowing in the following is defined as A, a; B, b; C, c; D, d; E, e.

  In this case, the excitation currents A, B, C, D, E and the excitation currents a, b, c, d, e are opposite in the excitation coils 1a, 1b, 1c, 1d, 1e for the corresponding alphabets. Indicates the current flowing in the direction. Further, for example, the time when the exciting current A flows through the exciting coil 1a is referred to as an exciting phase A, and the time when the opposite direction of the exciting current a flows is referred to as an exciting phase a. The same applies to the exciting coils 1b to 1e as in the case of the exciting coil 1a.

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

  Next, the display of the excitation phase when positioning the motor rotor (rotor) of the stepping motor 1 at each step position will be described. In addition, in order to simplify the expression, the excitation current is simultaneously supplied to a plurality of excitation coils of the five phases of excitation coils 1a to 1e to thereby combine the excitation phases when performing multiphase excitation. It is called an excitation pattern (excitation set).

  For example, simultaneously exciting two phases of the excitation phase A and the excitation phase B is referred to as two-phase excitation, and is referred to as an excitation pattern AB. The simultaneous excitation of the excitation phase A, the excitation phase B, the excitation phase C, and the excitation phase D is called four-phase excitation, which is referred to as an excitation pattern ABCD. Furthermore, in order to realize four-phase excitation, the excitation pattern BC and the excitation pattern AD are shifted in time and sequentially excited to realize four-phase excitation by combining two-phase excitation, a combination excitation pattern It will be written as BC-AD.

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

  Then, when the command pulse CWP is input, the excitation phase is changed 10 times by changing the excitation pattern in the following order: ABCD → BCDE → CDEa → CDab → DEab → EAbc → abcd → bccde → cdeA → deAB → eABC. The motor rotor can be step-driven (stepped) 10 steps of 0.72 ° at full-step position, and can rotate (normally rotate) 7.2 °, which is one electrical angle.

  Furthermore, the motor rotor can be rotated 360 °, that is, just one rotation at the mechanical angle, by repeating the step of the 10 full step positions 50 times. When the command pulse CCWP is input, the motor rotor can be reversed by changing the excitation phase in the order opposite to the above.

  As described above, the drive device 10 of the present embodiment for stepping driving the five-phase stepping motor 1 outputs the excitation pattern for exciting the excitation coils 1a to 1e by the input of the command pulse CWP or CCWP. And a switching unit 40 as an output stage having a plurality of switching devices (power devices) TR1 to TR10 and controlling ON / OFF of each of the switching devices TR1 to TR10 in accordance with the excitation pattern output from the excitation pattern output unit 30 And a motor current control unit 50 for performing constant current control of the output stage chopper type of the five-phase stepping motor 1.

  The excitation pattern output unit 30 of the present embodiment counts an input command pulse and manages an address corresponding to the electric angle position (step position) 31; an address position management unit (address counter) 31; A motor rotational speed management unit (speed measurement counter) 32 that manages the rotational speed of the stepping motor 1 by counting CCWPs, an excitation cycle counter unit 33 that manages a fixed unit excitation cycle T, and excitation that stores multiple excitation sequences An excitation pattern is selected from a pattern storage unit (memory) 34 and an excitation pattern storage unit 34, and an excitation pattern selection unit 35 for outputting an excitation pattern per unit excitation cycle T according to the excitation sequence; And a non-excitation processing unit 36 for outputting an excitation signal or a non-excitation signal according to a signal from the Current flowing through the exciting coil and a determining current saturation judgment section 37 that it has saturated.

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

  The electrical angle position management unit 31 in the excitation pattern output unit 30 manages an address corresponding to the electrical angle position (step position), and the number of managed addresses is set according to the resolution of the microstep. For example, in the case of the present embodiment, the resolution is set to “1/40” which divides the full step angle (0.72 °) into 40. Therefore, as shown in FIG. 3, the number of addresses to be managed is set to 400 of “000” to “399” (10 full step drive times × 40 micro step division numbers). In the driving device 10 of the present embodiment, the resolution of the microsteps can be arbitrarily set by the user within a predetermined range, and the management of the address is performed based on the set resolution.

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

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

  The motor rotation speed management unit 32 counts the command pulses CWP and CCWP and manages the calculated rotation speed of the stepping motor 1 from the number of pulse inputs per unit time, and excites the value of the rotation speed to be managed. Output to the selection unit 35.

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

  Further, the excitation cycle counter unit 33 manages a sequence cycle ST configured by an integral multiple of a unit excitation cycle T, and controls the excitation sequence by the electrical angle position management unit 31 every time the sequence cycle ST is counted. It outputs a sequence switching command to switch (or maintain) according to the value of the address being processed. For example, when the resolution is set to 1/40 and the unit excitation cycle T is set to 13.12 μs, an excitation switching command is output every 13.12, and 524 in the low speed region and the medium speed region. A sequence switching command is output every 8 μs (13.12 μs × 40).

  The excitation pattern storage unit 34 includes a low speed excitation sequence as shown in FIGS. 7 and 8, a medium speed excitation sequence as shown in FIGS. 10 to 12, and a plurality of high speed as shown in FIGS. 14 to 16. A high-speed sequence group having an excitation sequence is stored.

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

  For example, in the excitation pattern storage unit 34 of the present embodiment (when resolution is 1/40), in order to microstep drive the stepping motor 1, 400 types of low speed corresponding to addresses "000" to "399" The excitation sequence is set and stored.

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

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

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

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

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

  On the other hand, the low-speed excitation sequence corresponding to the address of the microstep position set between the addresses of the full step position is a first combined excitation pattern combining two two-phase excitation patterns at one full step position and It is formed by combining a second combined excitation pattern in which two two-phase excitation patterns are combined at the next full step position with a ratio according to the step position.

  For example, as shown in FIGS. 3 and 7, the low-speed excitation sequences corresponding to the addresses "001" to "039" of the microstep positions set between the addresses "000" and "040" are A first combined excitation pattern BC-AD combining two two-phase excitation patterns that realize four-phase excitation ABCD at the full step position, and two two-phase excitation that realize four-phase excitation BCDE at the next full step position The second combined excitation pattern CD-BE in which the patterns are combined is combined and set at a ratio according to the step position.

  In this case, as the numerical value of the address increases, the number of times of the first combined excitation pattern BC-AD is gradually decreased, and the number of times of the second combined excitation pattern CD-BE is gradually increased. The low speed excitation sequence is set.

  In the same way, the low speed excitation sequence corresponding to each address of the microstep position is set by combining the first combined excitation pattern and the second combined excitation pattern at a predetermined ratio, similarly to the address "041" and thereafter. It is done.

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

  Further, as described above, 1.5 rps (90 rpm) is set as the first rotation speed (medium speed determination speed) in the drive device 10 of the present embodiment, but 1.0 rps (90 rps) is separately set. The value of 60 rpm) is also preliminarily set, and 1.5 rps and 1.0 rps can be switched by a switch. The setting of 1.0 rps is a preliminary setting when using a motor with a very large inductance of 1.4 A / phase, and is usually set to 1.5 rps.

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

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

  For example, as shown in FIG. 3 to FIG. 6 and FIG. 10, 10 types of medium speed excitation sequences are stored in the excitation pattern storage unit 34 of the present embodiment. It has an excitation pattern for 40 times in which a unit excitation cycle T is 40 cycles.

  In addition, each medium-speed excitation sequence has only a four-phase excitation pattern that realizes single four-phase excitation corresponding to each full step position by simultaneously exciting four phases. For example, in the present embodiment, the medium-speed excitation sequence corresponding to the addresses “000” to “039” positioned at one full step position when the command pulse CWP is input (CW direction) includes an excitation phase A and an excitation phase B , The excitation phase C, and the excitation phase D have only 40 phases of four phase excitation patterns ABCD in which four phases are simultaneously excited. By excitation of this four-phase excitation pattern ABCD, a torque vector of VA + VB + VC + VD is generated.

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

  On the other hand, when command pulse CCWP is input (CCW direction), the numerical value of the address positioned at one full step position is different from that when command pulse CWP is input (CCW direction), for example, as shown in FIG. In the medium-speed excitation sequence corresponding to addresses "001" to "040" positioned at one full step position, four phases of excitation phase B, excitation phase C, excitation phase D and excitation phase E are excited simultaneously It has 40 cycles of only the 4-phase excitation pattern BCDE.

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

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

  In this case, in the high inductance type high speed sequence group, as described later, the rotation speed at the time when it is determined by the current saturation determination unit 37 that the excitation current is saturated in the middle speed region ) Is a high-speed sequence group selected by the excitation pattern selection unit 35 when it is smaller than a predetermined first set value (2 rps).

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

  Similarly, for the stepping motor 1 with a rated current of 2.4 A / phase and for the stepping motor 1 with a 2.8 A / phase, respectively, a high inductance type high speed sequence group, a medium inductance type high speed sequence group, and And three types of high speed sequence groups of small inductance type high speed sequence groups are respectively set. In the present embodiment, three types of high-speed sequence groups are set for one rated current, but in the present invention, two types of high-speed sequence groups are set for one rated current. It is good and four or more types of high-speed sequence groups may be set.

  Also, for large, medium, and small high-speed sequence groups of each inductance type, a plurality of high-speed excitation sequences corresponding to the speed range of the rotational speed managed by the motor rotational speed management unit 32 are positioned at each full step position It is set corresponding to the address to be

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

  Specifically, the first high-speed excitation sequence 11 in the high-speed sequence group of the small inductance type of 1.4 A / phase is an excitation sequence selected when the rotational speed is in the range of 5.65 rps to less than 6.00 rps. It is. In the second high speed excitation sequence 12 to the sixth high speed excitation sequence 16, the rotational speed is in the range of 6.00 rps or more and less than 7.63 rps, in the range of 7.63 rps or more and less than 9.53 rps, or more than 9.53 rps. It is an excitation sequence for high speed selected in the range of less than 10.17 rps, in the range of not less than 10.17 rps and less than 10.90 rps, and in the range of not less than 10.90 rps. In this case, the rotational speed of 7.63 rps is defined as an ultra-high-speed determination speed at which the rotation of the motor tends to be delayed with respect to the switching of the excitation by the input of the command pulse.

  The high-speed excitation sequences 11 to 16 in the high-speed sequence group of the small inductance type of 1.4 A / phase are two-phase excitation excitation patterns (for example, two-phase excitation patterns BC) positioned at one full step position. , And other combinations of excitation patterns of multiphase excitation. In this case, the two-phase excitation pattern (two-phase excitation pattern BC) to be positioned at one full step position is the first repetition number (that is, "00" times) of each high-speed excitation sequence 11-16 or The number of repetitions (eg, “00” times to “02” times) is set for several times.

  Also, as another multi-phase excitation pattern combined with such a two-phase excitation pattern (two-phase excitation pattern BC), as shown in FIG. 4, four phases are simultaneously excited and positioned at their full step positions Four-phase excitation pattern (for example, four-phase excitation pattern ABCD), Three-phase excitation pattern for positioning at a half step position between full step positions (for example, three phase excitation pattern BCD), Two-phase excitation pattern for positioning at the next full step position At least one excitation pattern in (for example, two-phase excitation pattern CD) and four-phase excitation pattern (for example, four-phase excitation pattern BCDE) for exciting four phases simultaneously and positioning at the next full step position is a stepping motor Combined according to the rotational characteristics and rotational speed of .

  By combining these other polyphase excitation patterns, as will be described later, it becomes possible to make the stepping motor 1 less susceptible to vibrations and out-of-step phenomena, and it becomes possible to smoothly rotate the stepping motor 1.

  Furthermore, the number of repetitions of the excitation pattern (excitation length of the entire magnetic sequence) set in each of the high-speed excitation sequences 11 to 16 is the number of repetitions set in the above-described low-speed excitation sequence or medium-speed excitation sequence (40 The number of repetitions of the excitation pattern is reduced as the high-speed excitation sequence is made smaller than the above and the rotational speed range becomes higher.

  Thereby, when the stepping motor 1 is step-driven in the high-speed region, the number of excitation patterns to be thinned out in the high-speed excitation sequence at the time of switching of the high-speed excitation sequence by changing the full step position (sequence update) It can be reduced.

  More specifically, in the present embodiment, switching (updating) of the excitation sequence is performed to step drive the stepping motor 1, but the timing at which the excitation sequence is switched will be described later. When the sequence switching command 35 receives a sequence switching command from the excitation cycle counter unit 33, and when the address managed by the electrical angle position management unit 31 switches to the numerical value of the full step position.

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

  In such a case, since the switching interval of the high-speed excitation sequence becomes short in the high-speed region, for example, the number of repetitions of the excitation pattern in the high-speed excitation sequence is 40 cycles (the high-speed excitation sequence has 40 excitation patterns) And before repeating the excitation pattern 40 times, the high speed excitation sequence is switched to the next full step position high speed excitation sequence, and the excitation pattern set to the number of times behind the high speed excitation sequence is It will be thinned out (the excitation pattern on the rear side will not be output).

  On the other hand, as described above, the number of repetitions of the excitation pattern in each high-speed excitation sequence is less than 40 cycles, and the number of repetitions of the excitation pattern is increased as the high-speed excitation sequence becomes faster. Can be reduced, and the number of excitation patterns to be thinned out in the high-speed excitation sequence can be reduced, and full step driving according to the high-speed excitation sequence can be stably performed.

  Here, specifically looking at the first high-speed excitation sequence 11 to the sixth high-speed excitation sequence 16 in the 1.4 A / phase small inductance type high-speed sequence group shown in FIG. The first high-speed excitation sequence 11 corresponding to the addresses "000" to "039" in the time (CW direction) has a two-phase excitation pattern BC set to a cycle of "00" times to "02" times; A four-phase excitation pattern ABCD is set in which “4 times to 26 times” cycles are set, and four phases are excited at the same time, and the total number of repetitions is formed from 27 excitation patterns.

  As described above, the first high-speed excitation sequence 11 has a two-phase excitation pattern BC in which the combined impedance of the entire coil is lower than the four-phase excitation pattern ABCD, thereby saturating the current in the high speed region as described later. The current can be made easier to flow through the stepping motor 1 than the excitation pattern of the excitation. As a result, it is possible to effectively extend the torque in a high-speed range where the rotational speed is 5.65 rps or more by suppressing the decrease rate of the combined torque accompanying the current saturation to a small value.

  In addition, when the first high-speed excitation sequence 11 includes not only the two-phase excitation pattern BC but also the four-phase excitation pattern ABCD at the subsequent stage, for example, when the high-speed excitation sequence is switched due to the address change of the full step position. While being able to exert a palliative action (when updated), it is possible to make it difficult for the stepping motor 1 to vibrate, it is possible to effectively prevent the step-out phenomenon.

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

  That is, in the second high-speed excitation sequence 12, the total number of repetitions is formed from 21 excitation patterns, and the number of repetitions of the excitation pattern is smaller than that of the first high-speed excitation sequence 11. In the second high speed excitation sequence 12 as well as the first high speed excitation sequence 11, the reduction ratio of the combined torque accompanying the current saturation is suppressed small, and the torque in the high speed region of 6.00 rps or more is effective. It is possible to stretch

  The third high-speed excitation sequence 13 selected in the rotational speed range of at least 7.63 rps (super high-speed determination speed) and less than 9.53 rps is a two-phase excitation pattern BC set to "00" cycles; A 4-phase excitation pattern ABCD is set to 01 "times to" 16 "cycles, and 4 phases are excited simultaneously, and it is set to" 17 "times to" 19 "cycles and positioned to the next full step position And the total number of repetitions is formed of 20 excitation patterns.

  As a result, it is possible to effectively extend the torque in a high speed region where the rotational speed is 7.63 rps or more. In addition, by having the two-phase excitation pattern CD positioned at the next full step position, the motor can be easily rotated to the next full step position in a high speed region higher than the ultra high speed judgment speed (7.63 rps). It can be effectively prevented that the rotation of the motor can not follow the switching of the excitation due to the input of.

  The fourth high-speed excitation sequence 14 selected in the range of rotational speed 9.53 rps to less than 10.17 rps, and the fifth high-speed excitation sequence selected in the range of rotational speed 10.17 rps to less than 10.90 rps 15 has the two-phase excitation pattern BC, the four-phase excitation pattern ABCD, and the two-phase excitation pattern CD in the proportions shown in FIG. It is possible to effectively extend the torque of (1) and to effectively prevent the rotation of the motor from being unable to follow the switching of the excitation by the input of the command pulse.

  The sixth high-speed excitation sequence 16 selected in the rotational speed range of 10.90 rps or more includes a two-phase excitation pattern BC set to a cycle of "00" times to "02" times, and "03" times to " Three-phase excitation pattern BCD, which is set to the cycle of 04 "times and is positioned at the half step position, and cycle of" 05 "times to" 13 "times, simultaneously excites the four phases to the next full step position A four-phase excitation pattern BCDE for positioning is provided, and the total number of repetitions is formed of 14 excitation patterns.

  The sixth high-speed excitation sequence 16 selected in such a high-speed range can effectively extend the torque in the high-speed range, and the rotation of the motor does not lag behind the input of the command pulse. The motor can be made easier to rotate to the next full step position.

  The excitation pattern selection unit 35 in the excitation pattern output unit 30 according to the present embodiment has a rotational speed managed by the motor rotational speed management unit 32 among the plurality of excitation sequences stored in the excitation pattern storage unit 34 described above. According to the address (electrical angle position) managed by the electrical angle position management unit 31, an appropriate excitation sequence is selected, and the excitation pattern is output to the switching unit 40 as an output stage according to the selected excitation sequence. It is outputted every unit excitation cycle T.

  The excitation / non-excitation processing unit 36 in the excitation pattern output unit 30 according to the present embodiment switches the excitation state and the non-excitation state according to the signal from the PWM constant current control circuit 51 of the motor current control unit 50. The output stage chopper type current control is performed to control the current flowing in 1a to 1e constant.

Here, constant current control of the output stage chopper type by the motor current control unit 50 and the excitation / non-excitation processing unit 36 will be described with reference to FIGS. 1 and 8 and the like.
The motor current control unit 50 of the present embodiment includes a power supply PS1 for supplying power for exciting the excitation coils 1a to 1e, a capacitor C1 for smoothing the voltage of the power supply PS1, and excitation coils 1a to 1e for performing constant current driving. It has a current detection resistor R1 that detects the current flowing to 1e, and a PWM constant current control circuit 51 that adjusts the time of excitation output to the excitation coils 1a to 1e according to the impedance of the excitation coils 1a to 1e. The configuration is the same as a conventional general motor current control unit that performs constant current control of the output stage chopper type.

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

  At this time, the information of the unit excitation cycle T is also output to the PWM constant current control circuit 51 of the motor current control unit 50, and generates a sawtooth wave having a plurality of substantially triangular vibrations for each unit excitation cycle T. At the same time, the PWM constant current control circuit 51 generates an error signal between the reference current value and the detection current generated at both ends of the current detection resistor R1 of FIG. 1 in order to obtain a constant excitation current. And the above-mentioned sawtooth level. Then, when the relationship of error signal ノ sawtooth wave is satisfied, the excitation output is made to be in the excitation state by the excitation / non-excitation processing unit 36, and a predetermined current is supplied to the excitation coil (the excitation coil is excited).

  If the relationship of error signal <sawtooth wave is satisfied, the PWM constant current control circuit 51 outputs a signal, and the excitation / non-excitation processing unit 36 causes the excitation output to be in the non-excitation state. In particular, in this non-excitation state, all the terminals are connected to the positive electrode as shown in (a) and (b) of FIG. 9 so that the terminals of the exciting coils 1a to 1e are not in the high impedance state. Hereinafter, this state is referred to as “positive OFF” or all terminals are connected to the negative electrode (hereinafter, this state is referred to as “negative OFF”). By performing such "positive OFF" or "negative OFF", it is possible to reduce the overshoot of the current at the time of switching the excitation output, improve the damping characteristics, and reduce vibration and noise. be able to.

  In the present embodiment, when the excitation output is set to the non-excitation state by the excitation / non-excitation processing unit 36, "positive OFF" may be always selected in all the non-excitation states, or "negative OFF" "" May be selected. Alternatively, in the non-excitation state, "positive OFF" and "negative OFF" may be switched regularly (for example, alternately), or even if "positive OFF" and "negative OFF" are switched randomly. good.

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

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

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

  For example, in the case of exciting the exciting coils 1a to 1e with a four-phase excitation pattern in the middle speed region, if the rotational speed of the stepping motor 1 becomes faster, the impedance of the exciting coil becomes higher. For this reason, when the rotation of the stepping motor 1 becomes faster than a certain rotation speed, the excitation pattern is switched before the current rises to a predetermined magnitude, and a sufficient torque can not be obtained. Thus, the state in which the excitation pattern is switched before the current rises to a predetermined magnitude is the state in which the current is saturated. The rotational speed at which the current reaches saturation differs depending on the motor characteristic of the stepping motor.

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

  Furthermore, the second determination unit of the current saturation determination unit 37 determines whether the flag 1 is set or not by the processing of the first determination unit, and the state in which the flag 1 is set is maintained at three unit excitation cycles T. It is determined that the current flowing to the stepping motor 1 has reached a current saturation state where the current flowing to the stepping motor 1 is saturated and stops flowing to a predetermined size, and the flag 2 is set.

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

  As described above, instead of setting a predetermined speed as the medium speed judgment speed in advance, for example, the medium speed judgment section which judges that the rotational speed of the stepping motor is in the middle speed region in the excitation pattern output unit 30. It is also possible to include (not shown), and in this case, the medium speed determination unit determines the excitation duty ratio of the excitation output (ie, within the unit excitation cycle T represented by “excitation output time / unit excitation cycle T”). Determine whether the ratio of the excitation output time (ON time) exceeds 60%, and check the state of the flag 1 and the medium speed first determination unit that sets the flag 1 when the ratio exceeds 60%. And a medium speed second determination unit that sets the flag 2 if the state in which the flag 1 is set up continues for three unit excitation cycles T.

  In such a medium speed judgment unit, the medium speed first judgment unit measures the ON time, and maintains the flag 1 turned down state when the excitation duty ratio does not exceed 60%. When the duty ratio exceeds 60%, the flag 1 is set. Also, for example, if it is determined that the excitation duty ratio has become 60% or less after the flag 1 is raised, processing is performed to turn the flag 1 down again. Furthermore, in the case where the medium speed second judgment unit judges whether the flag 1 is standing or falling by the processing of the first judgment unit, and the state where the flag 1 is held is maintained at three unit excitation cycles T. It is possible to output a signal of the medium speed region to the excitation pattern selection unit 35 by performing the process of setting the flag 2 by determining that the rotational speed of the stepping motor is in the medium speed region.

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

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

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

  In the excitation pattern selection unit 35 of the excitation pattern output unit 30, among the plurality of excitation sequences stored in the excitation pattern storage unit 34, the rotational speed output from the motor rotational speed management unit 32, and the electrical angle position management unit An excitation sequence meeting the conditions is selected based on the address value output from 31 and the excitation pattern is sequentially output for each unit excitation cycle T according to the selected excitation sequence.

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

  Thereby, in switching unit 40, ON and OFF of switching elements TR1 to TR10 are controlled according to the excitation pattern output from excitation pattern selection unit 35 and the signal from excitation / non-excitation processing unit 36, thereby controlling the excitation coil. By switching the excitation, the stepping motor 1 can be driven step by step.

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

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

  Thereby, in the exciting coils 1a to 1e, by alternately repeating the two sets of excitation patterns BC and excitation patterns AD, a torque vector of four-phase excitation ABCD by synthesis is generated, and the motor rotor has an address "000". It can be positioned at the full step position.

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

  For example, when the sequence switching command is received after performing the excitation pattern of the low speed excitation sequence corresponding to the address "000" 40 times, if the address of the electrical angle position management unit 31 is "000", the address Select the low speed excitation sequence corresponding to "000", and perform the excitation pattern of the low speed excitation sequence 40 times.

  On the other hand, when the sequence switching command is received, if the address of the electrical angle position management unit 31 is counted up to "001" by the input of the command pulse CWP, the low speed excitation sequence corresponding to the address "001" Is selected to switch the excitation sequence, and 40 excitation patterns are output in accordance with the low-speed excitation sequence corresponding to "001".

  In this case, as described above, each of the low-speed excitation sequences corresponding to the addresses “001” to “039” is a first combination of two two-phase excitation patterns that realize four-phase excitation ABCD at the full step position. A combination excitation pattern BC-AD and a second combination excitation pattern CD-BE combining two two-phase excitation patterns that realize four-phase excitation BCDE at the next full step position, at a ratio according to the step position It sets combining (refer FIG.3 and FIG.7).

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

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

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

  As a result, the stepping motor 1 can be stably microstep driven in the low speed region, and an appropriate torque can be stably ensured. Also, for example, even if the rotational speed of the stepping motor 1 increases in the low speed region, the excitation sequence corresponding to the address of the full step position is prevented from being thinned when updating the excitation sequence, and the address of the microstep position The micro-step drive can be smoothly performed by reducing the thinning of the excitation sequence corresponding to.

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

  In this case, the excitation sequence is updated each time a sequence switching command is received as described above and each time the address of the electrical angle position management unit 31 is switched to the address corresponding to the full step position. When the cycle of switching the address of the full step position becomes shorter than the fixed cycle in which the sequence switching command is output, the excitation sequence is updated at the full step position. It can be synchronized with the timing of address switching.

  Then, in such a low speed region, the excitation sequence update is synchronized with the timing at which the address of the full step position is switched, so that the vibration or vibration when switching from micro step driving in the low speed region to full step driving in the medium speed region. While being able to make it hard to produce a step-out phenomenon, the constant velocity rotation property of step drive can be maintained stably.

  In this medium-speed range, as shown in FIG. 3, FIG. 10 and FIG. 11, for example, when the address managed by the electrical angle position management unit 31 at the time of inputting the command pulse CWP is "000" to "039". The excitation pattern selection unit 35 generates a medium speed excitation sequence corresponding to addresses "000" to "039" from the plurality of medium speed excitation sequences stored in the excitation pattern storage unit 34, that is, excitation phases A to The medium speed excitation sequence having 40 cycles of only the four phase excitation pattern ABCD in which four phases of D are excited simultaneously is selected, and the four phase excitation pattern ABCD is selected every unit excitation cycle T according to the selected medium speed excitation sequence. It outputs to the switching unit 40. Thereby, in the exciting coils 1a to 1e, a torque vector of four-phase excitation ABCD can be generated, and the motor rotor can be positioned at the full step position.

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

  Then, when the address of the electrical angle position management unit 31 is counted up from “039” to the address “040” corresponding to the full step position by the input of the command pulse CWP, the excitation pattern selection unit 35 generates the address “040”. By selecting the medium-speed excitation sequence corresponding to 40 cycles, that is, only the 4-phase excitation pattern BCDE in which four phases of the excitation phases B to E are simultaneously excited. The medium-speed excitation sequence is switched (updated).

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

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

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

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

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

  In this case, the excitation cycle counter unit 33 outputs the excitation switching command every unit excitation cycle T, and outputs the sequence switching command at intervals according to the number of repetitions of the excitation pattern in the first high speed excitation sequence 11 .

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

  Similarly, while repeatedly outputting the excitation pattern according to the high-speed excitation sequence, the high-speed excitation sequence is switched every time the address of the electrical angle position management unit 31 is changed to the address corresponding to the full step position (update By doing this, the stepping motor 1 can be stably and full-step driven in a high speed region.

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

  Furthermore, the first high-speed excitation sequence 11 generates vibration of the stepping motor 1 by having not only the two-phase excitation pattern BC but also the four-phase excitation pattern ABCD in the rear cycle of “03” to “20”. While being able to make it hard, it is possible to prevent the step-out phenomenon more effectively.

  Here, although the case where the rotational speed managed by the motor rotational speed management unit 32 is a high speed area in the range of 5.65 rps to less than 6.00 rps has been described, for example, the electric angle position management unit 31 manages The second high-speed excitation sequence shown in FIG. 14 in the case where the address to be sent is "000" and the rotation speed managed by the motor rotation speed management unit 32 is in the range of 6.00 rps to less than 7.63 rps. 12, the second high-speed excitation having a two-phase excitation pattern BC set to a cycle of "00" to "02" and a four-phase excitation pattern ABCD set to a cycle of "03" to "20" Sequence 12 is selected. Thus, similarly to the first high-speed excitation sequence 11, it is possible to suppress the reduction rate of the torque accompanying the current saturation to a small value and increase the torque in the high-speed range of the rotational speed in the range of 6.00 rps to 7.63 rps it can.

  When the rotational speed managed by the motor rotational speed management unit 32 is in the range of not less than 7.63 rps and less than 9.53 rps, the third high-speed excitation sequence 13 shown in FIG. 14, that is, “00”. A two-phase excitation pattern BC set to the cycle, a four-phase excitation pattern ABCD set to the cycle of "01" to "16", and a cycle of "17" to "19", and the next full step position And a third high-speed excitation sequence 13 having a two-phase excitation pattern CD to be positioned.

  Thus, similarly to the first high-speed excitation sequence 11, the torque reduction rate in the high-speed range of the rotation speed range of 7.63 rps or more and less than 9.53 rps can be reduced while suppressing the reduction rate of the torque due to current saturation small. it can. In addition, the motor can be easily rotated to the next full step position in the high speed region, and the rotation of the motor can not effectively be prevented from following the switching of the excitation by the input of the command pulse.

  Furthermore, when the rotational speed managed by the motor rotational speed management unit 32 is in the range of 9.53 rps to less than 10.17 rps, the two-phase excitation pattern BC, the four-phase excitation pattern ABCD, and the two-phase excitation pattern CD are used. If the fourth high-speed excitation sequence 14 having the ratio shown in FIG. 14 is selected and the controlled rotational speed is in the range of 10.17 rps to 10.90 rps, the two-phase excitation pattern BC, 4 is selected. The fifth high-speed excitation sequence 15 having the phase excitation pattern ABCD and the two-phase excitation pattern CD in the proportions shown in FIG. 14 is selected. Furthermore, when the rotational speed managed by the motor rotational speed management unit 32 is in the range of 10.90 rps or more, the two-phase excitation pattern BC, the three-phase excitation pattern BCD, and the four-phase excitation pattern BCDE are shown in FIG. The sixth high-speed excitation sequence 16 having the ratio shown is selected.

  Even when the fourth high speed excitation sequence 14 to the sixth high speed excitation sequence 16 are selected, the torque in the high speed region of each rotational speed range can be increased, and the motor in each high speed region is The motor can be easily rotated to the full step position, and it can be effectively prevented that the rotation of the motor can not follow the switching of the excitation by the input of the command pulse.

  As another example, FIG. 15 shows five types of high-speed excitation sequences in which the rated current is set to a medium inductance type high-speed sequence group of 1.4 A / phase in this embodiment, and the rated current is 2.8 A FIG. 16 shows four types of high-speed excitation sequences set in the high-speed sequence group of the small inductance type of 1 / phase.

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

  Therefore, in any high-speed sequence group corresponding to the motor characteristics of stepping motor 1, it is possible to stably and effectively extend the torque in the high-speed region, and furthermore, when the high-speed excitation sequence is switched It is difficult to generate 1 vibration and to effectively prevent the step-out phenomenon, or to prevent the motor from failing to follow the switching of the excitation by the input of the command pulse, etc. 1.4A The same effect as in the case of the high speed sequence group of the phase / small inductance type can be obtained.

  Next, as a drive device for the stepping motor 1 according to the second embodiment of the present invention, a motor drive voltage conversion type (hereinafter referred to as “constant current control”) different from the output stage chopper type according to the first embodiment described above The drive device 20 in the following description will be described with reference to FIG.

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

  In the motor current control unit 70 according to the second embodiment, DV constant current control is performed. The motor current control unit 70 includes a power supply PS2 for supplying power for exciting the excitation coils 1a to 1e of the 5-phase stepping motor 1, a first capacitor C2a for smoothing the voltage of the power supply PS2, and excitation coils 1a to 1e. First and second current detection resistors R2a and R2b for detecting a flowing current, a PWM constant current control circuit 71 for performing constant current control based on the detected current, and a switching element TR11 capable of switching ON / OFF A power element drive circuit 72 for switching ON / OFF of the switching element TR11 based on an output signal from the PWM constant current control circuit 71, a diode D11 for bypassing an electromotive force emitted by the exciting coils 1a to 1e, and PWM A choke coil that generates intermittent motor drive voltage by inputting intermittent voltage With Le and L2 and the second capacitor C2b, an A / D converter 73 to send a motor driving voltage and digitizes the excitation pattern output unit 60.

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

  For example, when the current flowing through the first and second current detection resistors R2a and R2b decreases, the level of the error signal rises, so the on-time of the switching element TR11 is lengthened by the PWM constant current control circuit 71. Thereby, the voltage passing through the switching element TR11 is smoothed by the choke coil L2 and the second capacitor C2b to be a high voltage and applied to the exciting coils 1a to 1e, so control is performed to increase the exciting voltage. Can.

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

  In addition, the excitation pattern output unit 60 according to the second embodiment counts an input command pulse and manages an address corresponding to the electric angle position, and a stepping motor by counting the command pulse. A motor rotational speed management unit 62 that manages the rotational speed of 1; an excitation cycle counter unit 63 that manages a fixed unit excitation cycle T; an excitation pattern storage unit (memory) 64 that stores a plurality of excitation sequences; The excitation pattern selection unit 65 selects one excitation sequence from the storage unit 64 and outputs an excitation pattern according to the excitation sequence, and a current saturation determination unit 67 that determines that the current flowing in the excitation coil is saturated.

  In this case, regarding the electrical angle position management unit 61, the motor rotational speed management unit 62, the excitation cycle counter unit 63, and the excitation pattern selection unit 65, the respective processing units of the excitation pattern output unit 30 according to the first embodiment described above. And the detailed description is omitted here.

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

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

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

  In this case, the medium speed determination unit according to the second embodiment determines whether or not the excitation duty ratio of the excitation output exceeds 70%, and the medium speed first determination to set the flag 1 when the ratio exceeds 70%. And a medium-speed second determination unit that sets the flag 2 if the flag 1 continues to be set for three unit excitation cycles T after confirming the state of the flag 1. Therefore, the medium speed determination unit determines that the rotational speed is in the medium speed region when the state in which the flag 1 is raised is maintained for three unit excitation cycles T, and the medium speed determination unit 35 It is possible to output an area signal.

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

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

  In this case, the low speed excitation sequence is an excitation sequence in which positioning is performed at each step position of the full step position and the micro step position so as to microstep drive the stepping motor 1 in the low speed region.

  For example, when the resolution is 1/40, as shown in FIGS. 3 and 5, in order to microstep drive the stepping motor 1, 400 types of low speed corresponding to addresses "000" to "399" are used. The excitation sequence is set and stored. Each low-speed excitation sequence has a plurality of two-phase excitation patterns combined so that positioning can be performed at the electrical angle position of each address, and each excitation pattern is output from the excitation cycle counter section 63. Switching is performed based on the switching command.

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

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

  Furthermore, the low-speed excitation sequence corresponding to the address "040" of the next full step position is set by combining the excitation pattern CD and the excitation pattern BE at the same number or time ratio, thereby Implement phase excitation BCDE. Similarly, the low-speed excitation sequence corresponding to each address of the full step position has two two-phase excitation patterns that realize four-phase excitation by combination at the same number or time ratio.

  In addition, each low-speed excitation sequence corresponding to the microstep position addresses "001" to "039" set between the addresses "000" and "040" realizes the four-phase excitation ABCD of the full step position. A first combined excitation pattern BC-AD, which combines two two-phase excitation patterns, and a second combined excitation pattern CD, which combines two two-phase excitation patterns that realize a four-phase excitation BCDE at the next full step position. It is set by combining with BE at a ratio according to the step position.

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

  The medium-speed excitation sequence in the second embodiment is an excitation sequence for positioning the stepping motor 1 at each full-step position so as to drive the stepping motor 1 full-step in the medium-speed region. Ten medium-speed excitation sequences are stored which are positioned at respective full step positions (see FIGS. 3 and 5).

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

  Also, the medium-speed excitation sequence corresponding to the following addresses "040" to "079" is a four-phase excitation pattern in which four phases of excitation phase B, excitation phase C, excitation phase D, and excitation phase E are excited simultaneously. Has only BCDE. Similarly, each medium speed excitation sequence has only a four-phase excitation pattern for positioning at the corresponding full step position.

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

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

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

  In addition, each high-speed excitation sequence in the high-speed sequence group of small inductance type of 1.4 A / phase consists of an excitation pattern of two-phase excitation (for example, two-phase excitation pattern BC) positioned at one full step position and other multiples. It is formed by the combination with the excitation pattern of phase excitation (refer FIG.4 and FIG.6). In this case, the two-phase excitation pattern (two-phase excitation pattern BC) positioned at one full step position is the first step of each high-speed excitation sequence (ie, the first repetition number or the first repetition number of repetitions, or It is set to the initial time ratio).

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

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

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

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

  In addition, the excitation cycle counter section 63 of the excitation pattern output section 60 manages a constant unit excitation cycle T unrelated to the command pulse, and outputs an excitation switching command to the excitation pattern selection section 65 every unit excitation cycle T. . Furthermore, the excitation cycle counter unit 63 outputs a sequence switching command to the excitation pattern selection unit 65 every fixed sequence cycle ST (a cycle that is an integral multiple of the unit excitation cycle T).

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

  For example, when the stepping motor 1 is rotated in the low speed region, if the address managed by the electrical angle position management unit 61 is “000”, the excitation pattern selection unit 65 stores a plurality of excitation patterns stored in the excitation pattern storage unit 64. Select the low-speed excitation sequence corresponding to the address "000", that is, the low-speed excitation sequence in which the 2-phase excitation pattern BC and the 2-phase excitation pattern AD are combined at the same frequency or time ratio. According to the selected low-speed excitation sequence, the excitation pattern is output to the switching unit 40 while being switched at each unit excitation cycle T.

  Thereby, in the exciting coils 1a to 1e, by alternately repeating the two sets of excitation patterns BC and excitation patterns AD, a torque vector of four-phase excitation ABCD by synthesis is generated, and the motor rotor has an address "000". It can be positioned at the full step position.

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

  Likewise, while the excitation pattern output according to the low speed excitation sequence is performed in a predetermined cycle or predetermined time, for low speed corresponding to the address managed by the electrical angle position management unit 61 each time a sequence switching command is received. By updating (switching) the excitation sequence, it is possible to stably microstep drive the stepping motor 1 in a low speed region. Furthermore, in the second embodiment, the low speed excitation sequence is updated each time the sequence switching command is received, and the address of the electrical angle position management unit 61 corresponds to the full step position by the input of the command pulse CWP or CCWP. The low speed excitation sequence is updated each time the address is switched.

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

  Next, when the stepping motor 1 is rotated in the medium speed region, step driving of the stepping motor 1 is switched from micro step driving in the low speed region to full step driving. In this case, the excitation sequence is updated not only every time the sequence switching command is received as described above, but also every time the address of the electrical angle position management unit 61 is switched to the address corresponding to the full step position. Similarly to the first embodiment described above, when switching from microstep driving in the low speed region to full step driving in the medium speed region, it is possible to make it difficult to cause vibration and stepout phenomenon, and Constant speed rotation can be stably maintained.

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

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

  Likewise, while repeatedly outputting the four-phase excitation pattern according to the medium-speed excitation sequence, the medium-speed excitation sequence is performed each time the address of the electrical angle position management unit 61 is changed to an address corresponding to the full step position. As a result, the stepping motor 1 can be stably and fully step-driven in the medium speed region by switching the above, and the combined torque by the four-phase excitation can be appropriately secured.

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

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

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

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

  Further, when the rotational speed managed by the motor rotational speed management unit 62 is larger than the predetermined rotational speed range, based on the rotational speed, among the second high speed excitation sequence to the sixth high speed excitation sequence, , One corresponding high speed excitation sequence is selected.

  Thus, as in the case of the first embodiment, it is possible to stably and effectively extend the torque in each speed range of the high speed region, and further, when the high speed excitation sequence is switched, stepping Vibration of the motor 1 can be made hard to occur, and effects such as preventing the step-out phenomenon effectively and preventing the motor's rotation from following the switching of the excitation by the input of the command pulse can also be obtained. .

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

  In this case, the torque characteristics of the stepping motor obtained by the two drive devices were compared by stepping driving the stepping motor at various rotation speeds and measuring the torque of the stepping motor obtained at a predetermined rotation speed.

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

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

  Further, it was found that, when using the driving device 10 of the present invention which can obtain a larger torque in the high speed region, it is possible to accelerate about 1.5 times as fast as using the conventional driving device. . If such speeding up is possible, for example, in the drive device 10 of the present invention of DC 24 V input type which is not the target of constant voltage command, high speed characteristics equivalent to the conventional drive device of DC 36 V input type can be obtained. Become.

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

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

  As shown in FIG. 19, in the low speed region (for example, the region where the rotation speed is greater than 0 rpm and less than 90 rpm) and the middle speed region (for example, the region where the rotation speed is 90 rpm or more and less than 339 rpm) Although the torque did not change, it was confirmed that using the drive device 10 of the present invention can obtain a larger torque than when using a conventional drive device in a high speed region where the rotational speed is 339 rpm or more.

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

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

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

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

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

  As shown in FIG. 21, in the drive device 20 of the present invention and the conventional drive device, the torque obtained in the low-speed region and the medium-speed region did not change as in the first and second embodiments. It has been confirmed that, in the high speed region, by using the driving device 20 of the present invention, a larger torque can be obtained than in the case of using the conventional driving device.

DESCRIPTION OF SYMBOLS 1 stepping motor 1a-1e Excitation coil 10 Drive device 11 1st high speed excitation sequence 12 2nd high speed excitation sequence 13 3rd high speed excitation sequence 14 4th high speed excitation sequence 15 5th high speed excitation sequence 16 6th high speed Excitation sequence for drive 20 Drive device 30 Excitation pattern output part 31 Electric angle position management part (address counter)
32 Motor speed management unit (speed measurement counter)
33 excitation cycle counter 34 excitation pattern storage (memory)
35 Excitation pattern selection unit 36 Excitation / non-excitation processing unit 37 Current saturation determination unit 40 Switching unit (output stage)
41 power element drive circuit 50 motor current control unit 51 PWM constant current control circuit 60 excitation pattern output unit 61 electrical angle position management unit 62 motor rotation speed management unit 63 excitation cycle counter unit 64 excitation pattern storage unit (memory)
65 Excitation pattern selection unit 67 Current saturation determination unit 70 Motor current control unit 71 PWM constant current control circuit 72 Power element drive circuit 73 A / D converter A, a Direction of excitation current flowing through excitation coil B, b Flow through excitation coil Direction of excitation current C, c Direction of excitation current flowing through excitation coil D, d Direction of excitation current flowing through excitation coil E, e Direction of excitation current flowing through excitation coil CWP, CCWP Command pulse C1 Capacitor C2 capacitor 1st capacitor C2b 1st 2Capacitors D1 to D11 Diode L2 Choke coil OUT1 to OUT5 Output terminal PS1, PS2 Power supply R1 Current detection resistor R2a 1st current detection resistor R2b 2nd current detection resistor T Unit excitation cycle TR1 to TR11 Switching element (power element)
VA, Va Torque vector VB, Vb Torque vector VC, Vc Torque vector VD, Vd Torque vector VE, Ve Torque vector

Claims (11)

A driving device for a stepping motor, wherein an excitation phase of an HB-type five-phase stepping motor in which five excitation coils are annularly connected is switched by input of a command pulse to step drive the stepping motor, and counting the command pulse A motor rotation management unit that manages the electrical angle position and rotation speed of the stepping motor, an excitation pattern storage unit that stores an excitation sequence having a plurality of excitation patterns, and an electric angle position that is managed by the motor rotation management unit And an excitation pattern selection unit that selects the corresponding excitation sequence based on the rotational speed from the excitation pattern storage unit, and a plurality of switching elements, and the excitation pattern of the excitation sequence selected by the excitation pattern selection unit By controlling ON / OFF of each switching element according to The drive device for a stepping motor and a switching unit for switching the excitation phase of said stepping motor,
A plurality of high-speed excitation patterns set by combining the excitation pattern of two-phase excitation and the excitation pattern of other multi-phase excitations in the excitation pattern storage unit, in which the synthetic impedance of the excitation phase is lower than that of four-phase excitation. The excitation sequence is stored,
When the excitation pattern selection unit is in a high speed region where the rotation speed managed by the motor rotation management unit is equal to or higher than a predetermined high speed determination speed higher than a current saturation rotation speed at which the current flowing in the stepping motor is saturated. It is preset to select the high speed excitation sequence corresponding to the electrical angle position,
A driving device for a stepping motor characterized in that. The excitation pattern storage unit stores a plurality of medium-speed excitation sequences having only four-phase excitation excitation patterns,
The excitation pattern selection unit corresponds to the electrical angle position when the rotation speed is a medium speed region in which the rotation speed is less than the high speed determination speed at a predetermined medium speed determination speed or more slower than the current saturation rotation speed. Preset to select the medium speed excitation sequence,
A driving device for a stepping motor according to claim 1.   The drive for a stepping motor according to claim 1 or 2, wherein the high-speed excitation sequence is set by combining the excitation pattern of the two-phase excitation with the excitation pattern of the four-phase excitation and / or the excitation pattern of the three-phase excitation. apparatus. The excitation pattern storage unit stores a high-speed sequence group having a plurality of high-speed excitation sequences corresponding to each rotational speed range of the high-speed region,
The excitation pattern selection unit is preset to select the corresponding high-speed excitation sequence from the high-speed sequence group based on the rotation speed.
The drive device for a stepping motor according to any one of claims 1 to 3.   5. The driving device for a stepping motor according to claim 4, wherein each high speed excitation sequence of the high speed sequence group is set such that the excitation length of the whole sequence is set shorter as the rotational speed range becomes higher.   The high-speed excitation sequence selected when the rotational speed is equal to or higher than a predetermined ultra-high-speed determination speed higher than the high-speed determination speed is an excitation pattern that forms a torque vector corresponding to one full step position and the next The stepping pattern according to claim 4 or 5, further comprising: an excitation pattern forming a torque vector corresponding to a full step position of the magnetic field and / or an excitation pattern forming a torque vector corresponding to a half step position between both full step positions. Motor drive unit. And a current saturation determination unit that determines that the current flowing through the stepping motor is saturated and detects the current saturation rotational speed.
A plurality of the high-speed sequence groups corresponding to the speed range of the current saturation rotational speed are stored in advance in the excitation pattern storage unit,
The excitation pattern selection unit is set in advance to select one high speed sequence group corresponding to the detected current saturation rotational speed from the plurality of high speed sequence groups.
The drive device for a stepping motor according to any one of claims 3 to 6. A driving method of a stepping motor for stepping driving the stepping motor by switching an excitation phase of an HB type 5-phase stepping motor in which five excitation coils are annularly connected by inputting a command pulse,
A plurality of excitation sequences for high speed, which are set by combining the excitation pattern of two-phase excitation and the excitation pattern of other multi-phase excitations, in which the composite impedance of the excitation phase is lower than the excitation pattern of four-phase excitation And storing the rotation speed controlled by the motor rotation management unit in a high speed region where the speed is higher than a predetermined high speed determination speed higher than the current saturation rotation speed at which the current flowing through the stepping motor is saturated. Selecting the high speed excitation sequence that corresponds to the electrical angle position;
And a driving method of a stepping motor. Storing in advance in the excitation pattern storage unit a plurality of medium-speed excitation sequences having only four-phase excitation excitation patterns;
The medium speed excitation sequence corresponding to the electrical angle position when the medium speed region is such that the rotational speed is less than the high speed determination speed at a predetermined medium speed determination speed or more slower than the current saturation rotation speed To choose,
9. A driving method of a stepping motor according to claim 8, comprising Storing in advance in the excitation pattern storage unit a high speed sequence group having a plurality of the high speed excitation sequences corresponding to each rotational speed range of the high speed region;
Selecting the corresponding high speed excitation sequence from the high speed sequence group based on the rotation speed in the high speed region;
10. The driving method of a stepping motor according to claim 8, comprising Storing in advance the plurality of high speed sequence groups corresponding to the speed range of the current saturation rotational speed in the excitation pattern storage unit;
Determining that the current flowing through the stepping motor is saturated to detect the current saturation rotational speed;
Selecting one high speed sequence group corresponding to the detected current saturation rotational speed from the plurality of high speed sequence groups;
The driving method of a stepping motor according to claim 10, comprising:

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