Control device for a rotating device, rotating device, and control method for a rotating device

Abstract

The present invention provides a control device for a rotating device, the rotating device, and a control method for the rotating device. Although the structure is simple, the rotational position control accuracy is high and it is possible to easily detect a situation where a rotation abnormality exists in the rotating device. The control device (10) of the rotating device (1) includes a drive circuit (40) that applies a drive voltage to a stepping motor (20) that rotates an output gear (74) of the rotating device, and a control circuit (30) that outputs a number of drive pulses corresponding to a drive target included in a drive instruction signal from the outside to the drive circuit. The control circuit has: a drive pulse output unit (61) that outputs a number of drive pulses corresponding to the drive target, a position information acquisition unit (52) that acquires position information from a potentiometer (75) that reads the rotational position of the output gear, and a rotation abnormality determination unit (59) that determines whether a rotation abnormality has occurred in the rotating device based on the position information acquired by the position information acquisition unit.

Description

Technical Field

[0001] The present invention relates to a control device for a rotating device, a rotating device, and a control method for a rotating device. Background Art

[0002] In the prior art, as a rotating device used as a so-called actuator, for example, a rotating device described in Patent Document 1 is known. The rotating device includes an output gear, a motor that drives the output gear, and a housing having an opening that communicates with the outside at a position corresponding to the output gear, and the output gear can be accessed from the outside of the housing via the opening.

[0003] (Prior Art Documents)

[0004] (Patent Documents)

[0005] Patent Document 1: JP2018-038250A. Summary of the Invention

[0006] (Problems to be Solved by the Invention)

[0007] In such a rotating device, a stepping motor is used to drive and control the output gear. That is, the output gear is driven and controlled to a target position by rotating the stepping motor until the number of pulses of the drive signal of the stepping motor reaches the number of pulses of the movement target. Since a rotating device using a stepping motor has high position control accuracy, fine control can be performed.

[0008] However, in a rotating device using a stepping motor, since there is no physical position information of the output gear, there is no method for detecting an abnormality (for example, idling) in the rotation of the output gear due to gear breakage or the like.

[0009] As a drive control method for a rotating device, in addition to the open-loop control method using a stepping motor as described above, a feedback control method based on a voltage detected by a potentiometer mounted on a rotating mechanism is also known.

[0010] In a rotating device using feedback based on a potentiometer, a voltage that changes corresponding to the rotation of the output gear is detected by the potentiometer, the current position of the output gear is determined based on the detected voltage, and the drive amount is feedback-controlled based on the determined current position, thereby driving and controlling to a target position. It can be said that in a rotating device using feedback based on a potentiometer, the physical current position of the output gear can be grasped.

[0011] However, in a rotating device using potentiometer-based feedback, the accuracy of position control greatly depends on the performance of the potentiometer. In a rotating device using potentiometer-based feedback, in order to improve the position control accuracy as in a stepper motor, for example, it is necessary to improve the detection sensitivity of the potentiometer. Therefore, it may be necessary to use an IC with high sensitivity characteristics, etc., which may cause the structure to become complicated.

[0012] The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a control device for a rotating device, a rotating device, and a control method for a rotating device, which have a simple structure, but have high accuracy in controlling the rotation position, and can easily detect the presence of a rotation abnormality in the rotating device.

[0013] (Technical means for solving the problem)

[0014] To solve the above problems, a control device for a rotating device according to an embodiment includes: a drive circuit that applies a drive voltage to a stepper motor that rotates an output gear of the rotating device; and a control circuit that outputs a number of drive pulses corresponding to a drive target included in a drive instruction signal from the outside to the drive circuit. The control circuit includes: a drive pulse output unit that outputs a number of drive pulses corresponding to the drive target included in the drive instruction signal; a position information acquisition unit that acquires position information from a position sensor that reads the rotation position of the output gear of the rotating device; and a rotation abnormality determination unit that determines whether the rotating device has a rotation abnormality based on the position information acquired by the position information acquisition unit.

[0015] In the control device for the rotating device described above, it may be that whenever the number of drive pulses output by the drive pulse output unit reaches a specified value, the position information acquisition unit acquires position information from a position sensor that reads the rotation position of the output gear of the rotating device.

[0016] In the control device for the rotating device described above, it may be that when a difference D between first position information last acquired by the position information acquisition unit and second position information currently acquired by the position information acquisition unit differs from an ideal difference C by an allowable value α or more, the rotation abnormality determination unit determines that the rotating device has a rotation abnormality.

[0017] In the control device of the above-described rotating device, it is possible that at each timing when the drive pulse output unit starts and ends the output of the drive pulse, the position information acquisition unit acquires position information from a position sensor that reads the rotational position of the output gear of the rotating device. When the difference D between the third position information acquired by the position information acquisition unit at the timing of starting the output of the drive pulse and the fourth position information acquired by the position information acquisition unit at the timing of ending the output of the drive pulse differs from the ideal difference C by more than the allowable value α, the rotation abnormality determination unit determines that a rotation abnormality has occurred in the rotating device.

[0018] In the control device of the above-described rotating device, it is possible that the control circuit further includes an output stop unit that stops the output of the drive pulse in the drive pulse output unit when the rotation abnormality determination unit determines that a rotation abnormality has occurred in the rotating device.

[0019] In the control device of the above-described rotating device, it is possible that the position sensor is a potentiometer that outputs a voltage corresponding to the rotational position as position information.

[0020] In the control device of the above-described rotating device, it is possible that the control circuit includes: a first counter that counts the number of drive pulses output by the drive pulse output unit; a first memory that stores the specified value; a comparator that compares the value counted by the first counter with the specified value stored in the first memory; and an instruction unit that, when the result of the comparison by the comparator is that the counted value is greater than the specified value, determines that the number of drive pulses has reached the specified value and issues an instruction to each part of the control circuit.

[0021] In the control device of the above-described rotating device, it is possible that the control device of the rotating device includes a rotation abnormality determination restriction unit that restricts the rotation abnormality determination unit from performing the determination when the rotational position of the output gear driven by the drive pulse is in a blind area where the position sensor cannot read the rotational position.

[0022] In the control device of the above-described rotating device, it is possible that the control circuit further includes an initial position abnormality determination unit that determines an initial position abnormality when the position information acquired from the position information acquisition unit at the time of power-on indicates that the rotational position of the output gear is in a blind area of the position sensor, and the control circuit notifies the external of the initial position abnormality determined by the initial position abnormality determination unit.

[0023] In the control device of the above-mentioned rotating device, it may be that, after the initial position abnormality determination unit determines that the initial position is abnormal, when the control circuit receives the initial drive command signal after the power is started, the drive pulse output unit, instead of outputting the drive pulses of a number corresponding to the drive target contained in the drive command signal, outputs the drive pulses until the position information acquisition unit is able to obtain the position information based on the rotation position read by the position sensor.

[0024] In the control device of the above-mentioned rotating device, it may be that the control device of the rotating device comprises: a position memory, which stores a current position composed of a combination of the rotational position of the output gear of the rotating device and the rotational speed of the output gear of the rotating device; a pulse counter, which counts the number of drive pulses output by the drive pulse output unit and outputs a pulse count value; and a circle counter, which outputs a circle count value, wherein the circle count value is a value obtained by counting the number of times a drive pulse corresponding to the pulse count value passes through a reference position within one circle of the position sensor in the positive direction from the current position of the position memory, and the current position of the position memory is updated using the pulse count value and the circle count value.

[0025] In the control device for the rotating device, the revolution counter may count down the revolution count value when the revolution counter passes through a reference position within one revolution of the position sensor in the reverse direction.

[0026] In order to solve the above problems, a rotating device described in one embodiment includes: a stepping motor, which is rotationally driven by a control device of the above rotating device; an output gear, which rotates in conjunction with the rotational motion of the stepping motor; and a position sensor, which detects the rotational position of the output gear.

[0027] In order to solve the above-mentioned problems, a control method for a rotating device described in one embodiment includes: a drive pulse output step, wherein a drive pulse is repeatedly outputted a number of times corresponding to a drive target for a drive circuit that applies a drive voltage to a stepper motor that rotates an output gear of the rotating device; a position information acquisition step, wherein, at a specified repetition time of the drive pulse output step, position information is acquired from a position sensor that reads the rotational position of the output gear of the rotating device; and a rotation abnormality determination step, wherein whether a rotation abnormality occurs in the rotating device is determined based on the position information acquired in the position information acquisition step.

[0028] In the control method of the above-mentioned rotating device, it may be that after the position information acquisition step, a blind area determination step is further included. In the blind area determination step, it is determined whether the rotation position of the output gear driven by the drive pulse is a position within the blind area of the position sensor where the rotation position cannot be read by the position sensor, and the rotation abnormality determination step is executed only when it is determined in the blind area determination step that the rotation position of the output gear is not a position within the blind area of the position sensor.

[0029] (Advantages of the Invention)

[0030] Although the control device, rotating device, and control method of the rotating device of the present invention have a simple structure, the rotation position control accuracy is high, and it is possible to easily detect the presence of rotation abnormalities in the rotating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram showing an example of the rotating device of the first embodiment.

[0032] Figure 2 It is a schematic structural diagram showing an example of the control device of the rotating device of the first embodiment.

[0033] Figure 3 It is a diagram showing a configuration example of a functional block implemented by the drive control unit 50 of the control circuit 30.

[0034] Figure 4 It is a flowchart for explaining the operation of the control device of the rotating device of the first embodiment.

[0035] Figure 5 It is a diagram for explaining the rotation abnormality determination.

[0036] Figure 6 It is a flowchart for explaining the operation of the control device of the rotating device of the second embodiment.

[0037] Figure 7 It is a diagram showing a configuration example of a functional block implemented by the drive control unit of the control circuit of the third embodiment.

[0038] Figure 8 It is a diagram for explaining the blind area of the potentiometer.

[0039] Figure 9 It is a flowchart showing the process of the initial setting operation when the power supply is started in the control device of the rotating device.

[0040] Figure 10 It is a flowchart showing the operation process for the first drive instruction after the power supply is started in the control device of the rotating device.

[0041] Figure 11 This is a flowchart for explaining the operation of the control device for the rotating device according to the third embodiment.

[0042] Figure 12 This is a flowchart for explaining the operation of the control device of the rotating device according to the fourth embodiment.

[0043] Figure 13 It is a diagram showing a modified example of the configuration of a functional block implemented by a drive control unit of the control circuit. DETAILED DESCRIPTION

[0044] Hereinafter, specific examples of the embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to common components in each embodiment, and repeated descriptions are omitted.

[0045] (First Embodiment)

[0046] First, a control device for a rotating device, a rotating device, and a control method for a rotating device according to a first embodiment will be described.

[0047] Figure 1 1 is a schematic structural diagram showing an example of a rotating device according to the first embodiment. Figure 1 As shown, the structure includes a control substrate 11, a stepping motor 20, an actuator output shaft 70, a first gear 71, a second gear 72, a third gear 73, an output gear 74, a potentiometer (an example of a position sensor) 75 and an FPC (flexible printed circuit) 76 in a frame 12.

[0048] The control substrate 11 carries the control device 10 of the rotating device 1, and is wired in such a manner that the mounted control device 10 is electrically connected to the stepping motor 20 and the potentiometer 75 via the FPC 76. The control device 10 applies a driving voltage to the stepping motor 20, thereby rotating the output shaft of the stepping motor 20. The control device 10 of the rotating device of this embodiment can receive the voltage corresponding to the rotation position read by the potentiometer 75 as position information, but does not use the received position information for rotation driving (rotation driving is not performed by feedback based on the position information).

[0049] The stepping motor 20 is provided with a first gear 71 on its output shaft. When the first gear 71 is driven to rotate by the stepping motor 20, the second gear 72 and the third gear 73 rotate in conjunction. When these gears 71, 72, 73 rotate, the output gear 74 also rotates in conjunction with them.

[0050] The output gear 74 has an actuator output shaft 70, and the actuator output shaft 70 is connected to an external driven object. In addition, a potentiometer 75 is provided on the output gear 74, and by measuring the voltage value that changes according to the rotation position, the rotation position of the output gear 74 can be read.

[0051] Figure 2 It is a schematic structural diagram showing an example of a control device of the rotation device according to the first embodiment. Figure 3 It is a diagram showing a configuration example of a functional block implemented by the drive control unit 50 of the control circuit 30. The control device 10 of the rotation device 1 is configured as follows Figure 2 As shown, it is configured to include a control circuit 30 and a drive circuit 40.

[0052] A drive instruction signal (command) is input to the control circuit 30 from the outside via LIN (Local Interconnect Network) or the like. The drive instruction signal includes a drive target and is used to drive the stepping motor 20 so that the driven object connected to the actuator output shaft 70 performs a desired action. The drive target may be the number of rotation steps of the stepping motor 20, the rotation amount of the actuator output shaft 70, or the rotation position of the actuator output shaft 70, and is not particularly limited.

[0053] The control circuit 30 includes a drive control unit 50 that outputs a drive pulse corresponding to the drive target included in the drive instruction signal as a control signal to the drive circuit 40, and the drive circuit 40 includes a motor drive unit 41 that applies a drive voltage for driving the stepping motor 20.

[0054] The output of the potentiometer 75 that reads the rotation position of the output gear 74 is input to the drive control unit 50.

[0055] The drive control unit 50 includes hardware components such as a processor such as a CPU, various memories such as a ROM and a RAM, a timer (counter), an A / D conversion circuit, an input / output I / F circuit, and a clock generation circuit, and each component is constituted by a program processing device (for example, a microcontroller: MCU) connected to each other via a bus or a dedicated line.

[0056] The drive control unit 50 performs various operations by the processor in accordance with a program stored in a storage device (not shown) such as a memory and controls peripheral circuits such as the A / D conversion circuit and the input / output I / F circuit, thereby realizing Figure 3 the configuration of each functional unit shown. That is, as Figure 3As shown, the drive control unit 50 includes an instruction unit (an example of a rotation abnormality determination unit) 51, an AD converter (ADC: an example of a position information acquisition unit) 52, an A memory 53, a pulse counter 54, a position memory 55, an N counter 56, a first comparison unit 57, an X memory 58, a second comparison unit 59, a third comparison unit 60, and a drive pulse output unit 61 as functional units. Each functional unit in the drive control unit 50 can perform various processes according to the instruction of the instruction unit 51.

[0057] When the instruction unit 51 receives a drive instruction signal from the outside, it outputs a number of drive pulses corresponding to the drive target included therein to the drive pulse output unit 61, and outputs a counting instruction to the pulse counter 54 and the N counter 56. The instruction unit 51 can calculate the number of drive pulses required to reach the drive target contained in the drive instruction signal as the target count value.

[0058] The instruction unit 51 can acquire the position information A (reference position information, first position information) at a specified time such as when starting to output drive pulses, and issue an instruction to the AD converter 52 to store the acquired position information A in the A memory 53. The instruction unit 51 can issue comparison instructions to the first comparison unit 57, the second comparison unit 59, and the third comparison unit 60 at a specified time. The instruction unit 51 performs various judgment controls based on the comparison results received from the respective comparison units 57, 59, and 60.

[0059] The AD converter 52 receives an instruction from the instruction unit 51, acquires the voltage (position information) corresponding to the rotational position input from the potentiometer 75, performs AD conversion, and stores it in the A memory 53 as the first position information. Thereafter, at the time of rotation abnormality determination, the AD converter 52 receives an instruction from the instruction unit 51, performs AD conversion on the voltage corresponding to the rotational position input from the potentiometer 75, and transfers it to the second comparison unit 59 as the second position information. It should be noted that by transferring the second position information acquired at the time of rotation abnormality determination to the second comparison unit 59 and overwriting the information stored in the A memory 53 as the first position information, the reference position can be updated at the time of rotation abnormality determination.

[0060] The drive pulse output unit 61 receives an instruction from the instruction unit 51 and outputs drive pulses to the motor drive unit 41 of the drive circuit 40.

[0061] The pulse counter 54 receives an instruction from the instruction unit 51, increments the counter, and transfers the incremented count value to the position memory 55. The position memory 55 adds the acquired count value to the stored position (position count value), stores (updates) the obtained value as the information of the rotational position (position count value) again, and then notifies the instruction unit 51 that it has been stored.

[0062] The N-counter 56 receives an instruction from the instruction unit 51, increments the counter, and holds the incremented count value (N-count value). The first comparison unit 57 receives an instruction from the instruction unit 51, compares the specified value (also referred to as the X value) held in the X memory 58 with the N-count value held in the N-counter 56, and passes the comparison result to the instruction unit 51.

[0063] The X value held in the X memory 58 serves as a reference for determining the rotation abnormality of the rotating device. This X value can be set based on the performance of the potentiometer 75, and its value is not particularly limited. By increasing this X value when the performance of the potentiometer 75 is low and decreasing this X value when the performance of the potentiometer 75 is high, the rotation abnormality can be accurately determined with an appropriate resolution corresponding to the performance of the potentiometer 75.

[0064] The second comparison unit 59 receives an instruction from the instruction unit 51, compares the position information A (first position information) stored in the A memory 53 with the position information B (second position information) obtained via the AD converter 52, and passes the comparison result to the instruction unit 51.

[0065] The third comparison unit 60 receives an instruction from the instruction unit 51, compares the position count value held in the position memory 55 with the target count value to be driven as a target, and returns the comparison result to the instruction unit 51.

[0066] The operation of the control device of the rotating device according to the first embodiment described above will be described. Figure 4 It is a flowchart for explaining the operation of the control device of the rotating device according to the first embodiment. In the control device 10 of the rotating device 1 in the present embodiment, the instruction unit 51 starts Figure 4 its operation by receiving a drive instruction signal (command) from the outside (S101).

[0067] When the instruction unit 51 receives a drive instruction, first, prior to the drive pulse emission process, it performs various setting operations for appropriately determining the rotation abnormality. Specifically, the instruction unit 51 obtains the current position from the position memory 55 (calls the current position) (S102). Thereafter, the instruction unit 51 issues an instruction to the AD converter 52 to obtain the position information read by the current potentiometer 75. The AD converter 52 obtains the position information A (an example of the first position information) read by the potentiometer 75 as a reference position, and stores the obtained position information A in the A memory 53 (S103). In addition, at the time of step S103, the N-counter 56 receives a reset instruction from the instruction unit 51 and resets the value of the N-counter to 0.

[0068] After step S103, the drive pulse output unit 61 receives from the instruction unit 51 an instruction to emit an output pulse of the drive pulse output unit 61, and emits a drive pulse to the motor drive unit 41 of the drive circuit 40 (S104). Thus, the stepping motor 20 is driven and controlled by applying a drive voltage to the motor drive unit 41.

[0069] After step S104, the pulse counter 54 receives from the instruction unit 51 an instruction to count the output pulses, increments the counter (S105), and transfers the incremented count value to the position memory 55. If the position memory 55 receives the incremented count value, it updates the current position (position count value) based on the position called in step S102 and the received count value (S106). Thus, the position count value is updated until the drive target (target count value) is reached.

[0070] After step S106, the N counter 56 receives from the instruction unit 51 an instruction to count the N counter, and increments the N counter value (S107). Thus, the N counter value reflects the number of drive pulses emitted at each predetermined rotation abnormality determination interval.

[0071] After step S107, the first comparison unit 57 receives from the instruction unit 51 a comparison instruction, compares the N counter value of the N counter 56 with the X value held in the X memory 58 (determines whether the N counter value > X value) (S108), and transfers the comparison result to the instruction unit 51. Thus, since the X value that is the reference for determining the rotation abnormality of the rotating device is compared with the N counter value reflecting the number of drive pulses emitted, it is possible to determine the timing of the rotation abnormality determination to be performed at each predetermined rotation abnormality determination interval.

[0072] When the instruction unit 51 receives a comparison result indicating that the N counter value is greater than the X value (S108: Yes), it determines that it is a predetermined rotation abnormality determination interval and executes a rotation abnormality determination process. Specifically, the instruction unit 51 requests the AD converter 52 to obtain the current position information, and issues a comparison instruction to the second comparison unit 59. When the second comparison unit 59 receives the comparison instruction from the instruction unit 51, it obtains the position information A stored in the A memory 53 and the current position information (an example of the second position information) B obtained by the AD converter 52 (S109). After step S109, the second comparison unit 59 calculates the difference D between the position information A and the position information B (= B - A or = A - B), and compares the calculated difference D with the values ((C - α) and (C + α)) obtained by adjusting the previously held ideal difference C by the allowable value α (S110), and transfers the comparison result to the instruction unit 51. As the allowable value α, any value can be set. In addition, the absolute values of -α and +α can be set to different values.

[0073] When the instruction unit 51 obtains a comparison result indicating that the calculated difference D is outside the range of the value obtained by adjusting the ideal difference C by the allowable value α (i.e., (C - α) < D < (C + α) is not satisfied) (S110: No), it determines that a rotation abnormality has occurred in the rotation device, turns on (ON) the error flag (S111), and stops the output of the drive pulse to the drive pulse output unit 61. As a result, the drive of the stepping motor 20 stops (S112). In addition, the process of turning on the error flag in step S111 can also be omitted.

[0074] Here, use Figure 5 to further illustrate the rotation abnormality determination process. Figure 5 is a diagram for explaining the rotation abnormality determination. In Figure 5 's example, the following situation is illustrated: The number of command pulses for one drive of the stepping motor output according to the drive command signal is 20 pulses, the specified rotation abnormality determination interval of the pulses is 10 pulses (i.e., the X value is 9), and the allowable value is α. In addition, this example only shows an example of the numerical value and is not limited thereto.

[0075] In Figure 5 , the number of command pulses to the motor is shown on the horizontal axis, and the position sensor output value is shown on the vertical axis. In addition, along the horizontal axis, the determination counter N (N counter value), the rotation abnormality determination time, and the movement start time are shown. In this example, it can be seen that the N counter value is updated every 10 counts, and the determination time becomes every 10 pulses (counts). In addition, in this figure, it is shown that in the A memory 53, the position information A1, A2, A3 is stored as the first position information as the reference position. The position information B1, B2, B3 represents the ideal second position information corresponding to the position information A1, A2, A3 respectively.

[0076] In the control device 10 of the rotation device 1 in the present embodiment, during normal operation, as shown in the graph of the normal output value transition example in Figure 5 , the output value of the position sensor (the value of the position information) increases in proportion to the increase in the number of drive pulses. However, if a rotation abnormality occurs, a value deviated from this graph will be presented.

[0077] For example, take the case where "Ba" and the case where "Bb" are obtained as the current position information B at the determination time of the 30th step (step) as an example for explanation.

[0078] In this case, at the previous determination time at the determination time of step 30, in the A memory 53, the position information A3 is stored as the first position information as the reference position. Therefore, when "Ba" is obtained as the current position information (an example of the second position information) B, the difference D1 becomes Ba - A3. This difference D1 is within the range of the value obtained by adjusting the ideal difference C by the allowable value α. Therefore, in this case, it is not determined that there is a rotation abnormality.

[0079] On the other hand, when "Bb" is obtained as the current position information (an example of the second position information) B, the difference D2 becomes Bb - A3. This difference D2 is outside the range of the value obtained by adjusting the ideal difference C by the allowable value α. Therefore, in this case, it is considered that the position "B3" corresponding to the number of output pulses has not been reached, and a rotation abnormality is determined.

[0080] On the other hand, in Figure 4 In step S108, when the instruction unit 51 receives the comparison result that the N counter value is not greater than the X value (S108: No), it can be determined that it is not the time for rotation abnormality determination. Similarly, when the instruction unit 51 obtains the comparison result that the calculated difference D is within the range of the value obtained by adjusting the ideal difference C by the allowable value α ((C - α) < D < (C + α)) (S110: Yes), it can be determined that the result of the rotation abnormality determination is determined to be normal. In these cases (S108: No and S110: Yes), the instruction unit 51 issues a comparison instruction to the third comparison unit 60 in order to determine the stop condition. When receiving the comparison instruction, the third comparison unit 60 compares the target count value with the position count value in order to determine whether to clear the stop condition (S113), and transmits the comparison result to the instruction unit 51.

[0081] When the instruction unit 51 receives the comparison result that the stop condition is cleared because the position count value has reached the target count value (S113: Yes), it ends the emission of the drive pulse (S112).

[0082] When the instruction unit 51 receives the comparison result that the stop condition is not cleared because the position count value has not reached the target count value (S113: No), it determines whether it is the time for rotation abnormality determination according to whether the comparison result received in step S108 is N counter value > X value (S114). When the result of the determination in step S114 is determined to be the time for rotation abnormality determination (S114: Yes), it returns to the process of step S103. When the determination result in step S114 is determined not to be the time for rotation abnormality determination (S114: No), it returns to the process of step S104.

[0083] For the control device of the rotating device, the rotating device, and the control method of the rotating device according to this embodiment, the control of the rotational position of the stepping motor has been performed by open-loop control based on a drive command signal as in the past. That is, the position information obtained by the position sensor is not used as the position information in normal motor driving, so it does not affect the level of position accuracy and high resolution in existing stepping motors. On the other hand, as long as the position information can determine the degree to which the output gear physically moves, there is no need for high-precision position detection like a position sensor for normal position detection, and a low-cost position sensor with relatively low precision can be used, so it can be implemented at low cost.

[0084] (Second Embodiment)

[0085] Next, the control device of the rotating device, the rotating device, and the control method of the rotating device according to the second embodiment will be described. In the first embodiment, the instruction unit 51 performs a rotation abnormality determination at a prescribed rotation abnormality determination interval, but in this embodiment, the instruction unit 51 performs a rotation abnormality determination after driving until the drive target is reached (the stop condition is cleared), which is different in this regard. In the second embodiment, for the components other than the instruction unit 51, a control device and a rotating device of the rotating device having the same configuration as that of the first embodiment can be adopted. For the second embodiment, only the configuration different from that of the first embodiment will be described, and the description of the configuration common to the first embodiment will be omitted.

[0086] Figure 6 is a flowchart for explaining the operation of the control device of the rotating device according to the second embodiment. Refer to Figure 3 and Figure 6 The operation of the control device 10 of the rotating device 1 in the second embodiment will be described. In the control device 10 of the rotating device 1 in the second embodiment, from Figure 6 step S201 to step S206, the same processing as steps S101 to S106 in the first embodiment is performed, and from Figure 6 step S210 to step S213, the same processing as steps S109 to S112 in the first embodiment is performed.

[0087] In this embodiment, the process from the emission of drive pulses (S204) to the update of the current position (S206) is repeated until the stop condition is cleared (S207: Yes).

[0088] When the instruction unit 51 determines that the stop condition is cleared (S207: Yes), it stops driving the stepping motor 20 (S208) and determines whether the determination condition is satisfied (S209). Specifically, the first comparison unit 57 receives a comparison instruction from the instruction unit 51, compares the N-counter value of the N-counter 56 with the X value of the X memory 58, and returns the comparison result to the instruction unit 51. When the N-counter value is greater than the X value, the instruction unit 51 determines that the determination condition is satisfied.

[0089] In the present embodiment, in step S203, the position information at the start time of the output of the drive pulse is acquired, and the acquired position information (an example of the third position information) A is stored in the A memory 53 as the information of the reference position. Further, in the rotation abnormality determination process, in step S210, the position information (an example of the fourth position information) B at the end time of the output of the drive pulse is acquired, and in step S211, the difference D from the position information A stored in the A memory 53 is calculated, and rotation abnormality determination is performed by comparison.

[0090] In the present embodiment, when the number of drive pulses is too small, the accuracy of rotation abnormality determination decreases. Therefore, by determining whether to execute the rotation abnormality determination process in step S209, it is possible to avoid a decrease in the accuracy of rotation abnormality determination. However, when the number of drive pulses for one drive of the stepping motor output according to the drive instruction signal is large enough, the process of step S209 is not necessarily required. In this case, the N-counter 56, the first comparison unit 57, and the X memory 58 of the control device shown can be omitted. Figure 3 shown.

[0091] As described above, according to the first embodiment and the second embodiment, it is possible to provide a control device for a rotating device, a rotating device, and a control method for a rotating device, which have a simple structure, but have high rotational position control accuracy, can easily detect a situation where the rotating device has a rotation abnormality, and can expand the rotation movable area.

[0092] On the other hand, in a rotating device that performs rotational position detection using a position sensor such as a potentiometer, since there is a blind spot where position information cannot be acquired within one revolution of the position sensor, and in addition, if it exceeds one revolution (360 degrees), the output value is reset, it is difficult to perform position management for more than one revolution. Therefore, as long as these regions where rotational position detection is difficult can be controlled as movable regions, the rotation movable area can be expanded.

[0093] Therefore, in the third embodiment and the fourth embodiment, these regions where position detection is possible but rotational position detection is difficult are controlled as movable regions, and the rotation movable area is expanded.

[0094] (Third Embodiment)

[0095] Here, a control device for a rotating device, the rotating device, and a control method for the rotating device according to the third embodiment will be described. Figure 7 FIG. is a configuration example of a functional block implemented by the drive control unit 50A of the control circuit 30 according to the third embodiment. In the present embodiment, except for using the drive control unit 50A instead of the drive control unit 50 (refer to Figure 2 ), the rotating device has the same configuration as that of the rotating device in the first embodiment, and redundant descriptions thereof are omitted.

[0096] In the third embodiment, the drive control unit 50A is implemented by a processor performing various operations according to a program stored in a storage device (not shown) such as a memory and controlling peripheral circuits such as an A / D conversion circuit and an input / output I / F circuit, Figure 7 to realize the configuration of each functional unit shown. That is, as shown in Figure 7 , in the drive control unit 50A, as functional units, there are provided an instruction unit (an example of a rotation abnormality determination unit, a rotation abnormality determination restriction unit, and an initial position abnormality determination unit) 51A, an AD converter (ADC: an example of a position information acquisition unit) 52, an A memory 53, a pulse counter 54, a position memory 55, an N counter 56, a first comparison unit 57, an X memory 58, a second comparison unit 59, a third comparison unit 60, a drive pulse output unit 61, a fourth comparison unit 62, a blind area memory 63, a fifth comparison unit 64, and a lap counter 65. Each functional unit in the drive control unit 50A can execute various processes based on an instruction from the instruction unit 51A.

[0097] When the instruction unit 51A receives a drive instruction signal from a superior controller (not shown; an example of an external device), it outputs a corresponding number of drive pulses to the drive pulse output unit 61 according to the drive target contained therein, and outputs a count instruction to the pulse counter 54 and the N counter 56. The instruction unit 51A can calculate the number of drive pulses for achieving the drive target contained in the drive instruction signal as a target count value.

[0098] The instruction unit 51A can acquire position information A (reference position information, first position information) at a specified time such as the start of output of drive pulses, and issue an instruction to the AD converter 52 to store the acquired position information A in the A memory 53. The instruction unit 51A can issue comparison instructions to the first comparison unit 57, the second comparison unit 59, the third comparison unit 60, the fourth comparison unit 62, and the fifth comparison unit 64 at a specified time. The instruction unit 51A performs various judgment controls based on the comparison results received from the respective comparison units 57, 59, 60, 62, 64.

[0099] The AD converter 52 receives an instruction from the instruction unit 51A, acquires the voltage (position information) corresponding to the rotational position input from the potentiometer 75, and stores the value after AD conversion (hereinafter, also referred to as the ADC value) as the first position information in the A memory 53. Thereafter, at the time of rotational abnormality determination, the AD converter 52 receives an instruction from the instruction unit 51A, and transmits the value (ADC value) obtained by AD-converting the voltage corresponding to the rotational position input from the potentiometer 75 to the second comparison unit 59 as the second position information. It should be noted that the second position information acquired at the time of rotational abnormality determination is transmitted to the second comparison unit 59 and overwrites the information stored in the A memory 53 as the first position information, so that the reference position can be updated at the time of rotational abnormality determination.

[0100] The drive pulse output unit 61 receives an instruction from the instruction unit 51A and outputs a drive pulse to the motor drive unit 41 of the drive circuit 40.

[0101] The pulse counter 54 receives an instruction from the instruction unit 51A, increments the counter, and transmits the incremented pulse count value to the position memory 55 and the lap counter 65. When receiving the pulse count value from the pulse counter 54, the lap counter 65 refers to the current rotational position (position count value: a value corresponding to 0 degrees to 360 degrees) of the output gear 74 stored in the position memory 55, adds the pulse count value received from the pulse counter 54 to the position count value, and incrementally counts the lap count value by the number of times the boundary (reference position) within one turn of the potentiometer 75 is passed in the forward direction and transmits it to the position memory 55. The position memory 55 stores (updates) the value obtained by adding the acquired pulse count value and lap count value to the position (position count value and lap count value) corresponding to the stored rotational position of the output gear 74 as the information (position count value and lap count value) of the rotational position, and notifies the instruction unit 51A that the storage has been completed. That is, the current position (position) of the position memory 55 is updated using the pulse count value and the lap count value.

[0102] The instruction unit 51A can, as needed, send the position stored in the position memory 55 to the upper-level controller as a status signal. In the rotating device 1 of the present embodiment, the current position (position) stored in the position memory 55 is managed by the position count value and the revolution count value. The position within the existing 360-degree rotation range (i.e., within 1 revolution) is managed by the position count value P. In the area where the rotation range exceeds 360 degrees (i.e., the area exceeding 1 revolution), the revolution count value n can also be used for management. When the brush of the potentiometer 75 rotates clockwise past the reference position (e.g., 0 degrees) (an example in the forward direction), the revolution count value n is incremented. When the brush of the potentiometer 75 rotates counterclockwise past the reference position (e.g., 0 degrees) (an example in the reverse direction), the revolution count value n is decremented. Regarding the position stored in the position memory 55, for example, when 3 revolutions are defined as 1000 positions, the current rotation position can be represented as the sum of n×(1000÷3) positions corresponding to the revolution count value n and (P÷360)×(1000÷3) positions corresponding to the position count value P. The instruction unit 51A can report the current position using the position count value P and the revolution count value n to the upper-level controller. Thus, the rotating device 1 of the present embodiment can also be used for mechanisms that require rotation of more than 360 degrees, such as a rack mechanism and a link mechanism. In addition, the reference position is not limited to 0 degrees and can be set to any angular position.

[0103] The N counter 56 receives an instruction from the instruction unit 51A, increments the counter, and holds the incremented count value (N count value). The first comparison unit 57 receives an instruction from the instruction unit 51A, compares the specified value (also referred to as the X value) held in the X memory 58 with the N count value held in the N counter 56, and returns the comparison result to the instruction unit 51A.

[0104] Based on the comparison result received from the first comparison unit 57, the instruction unit 51A determines whether it is the time to determine a rotation abnormality. If it is the time to determine a rotation abnormality, the instruction unit 51A instructs the second comparison unit 59 to execute a comparison process for determining a rotation abnormality.

[0105] The X value held in the X memory 58 becomes the reference for the time to determine a rotation abnormality of the rotating device 1. This X value can be set based on the performance of the potentiometer 75, and its value is not particularly limited. When the performance of the potentiometer 75 is low, this X value is increased. When the performance of the potentiometer 75 is high, this X value is decreased, so that a rotation abnormality can be accurately determined with an appropriate resolution corresponding to the performance of the potentiometer 75.

[0106] The second comparison unit 59 receives an instruction from the instruction unit 51A, compares the position information A (first position information) stored in the A memory 53 with the position information B (second position information) acquired via the AD converter 52, and returns the comparison result to the instruction unit 51A.

[0107] Based on the comparison result received from the second comparison unit 59, the instruction unit 51A determines whether a rotation anomaly exists. If there is no rotation anomaly, the instruction unit 51A instructs the third comparison unit 60 to execute a process for determining a stop condition.

[0108] The third comparison unit 60 receives an instruction from the instruction unit 51A, compares the position (position count value and revolution count value) held in the position memory 55 with the target count value that is the driving target, and returns the comparison result to the instruction unit 51A.

[0109] Based on the comparison result received from the third comparison unit 60, when there is a difference between the position and the target count value, the instruction unit 51A can determine that a drive pulse needs to be emitted, and when the position and the target count value match, the instruction unit 51A can determine that the stop condition is cleared.

[0110] At the moment of rotation anomaly determination, the fourth comparison unit 62 receives an instruction from the instruction unit 51A, compares the position count value indicating the rotational position of the output gear 74 after being driven by the drive pulse with the rotational position corresponding to the blind area of the potentiometer 75 stored in the blind area memory 63, and transfers the comparison result to the instruction unit 51A. When the instruction unit 51A issues an instruction to the fourth comparison unit 62, the position count value can be acquired from the position memory 55 and transferred to the fourth comparison unit 62.

[0111] Based on the comparison result received from the fourth comparison unit 62, the instruction unit 51A determines whether the rotational position of the output gear 74 after rotation by the stepping motor 20 is a position within the blind area of the potentiometer 75. When the instruction unit 51A determines that the rotational position of the output gear 74 is a position within the blind area of the potentiometer 75, it functions as a rotation anomaly determination restriction unit and controls in such a way that rotation anomaly determination is not performed even at the moment of rotation anomaly determination. That is, when the rotational position of the output gear 74 after rotation by the stepping motor 20 is a position within the blind area of the potentiometer 75 where the potentiometer 75 cannot read the rotational position, the instruction unit 51A functions as a rotation anomaly determination restriction unit and can control in such a way that rotation anomaly determination is not performed.

[0112] Figure 8This is a diagram for explaining the blind spot of the potentiometer 75. The blind spot of the potentiometer 75 will be described herein. When determining rotation abnormality in the rotation device 1 of the present embodiment, the first position information and the second position information compared by the second comparison unit 59 are values obtained by AD-converting the voltage corresponding to the rotation position input from the potentiometer 75. In the potentiometer 75, as Figure 8 shown, there is a region called the blind spot, that is, a region where voltage measurement cannot be performed for a part of all rotation positions. In the blind spot, the potentiometer 75 cannot read the rotation position. Therefore, when the rotation position of the output gear 74 is within the blind spot of the potentiometer 75, even if rotation abnormality determination is attempted, rotation abnormality determination cannot be accurately performed. Thus, in normal control, it is not regarded as a rotation movable region.

[0113] In the rotation device 1 of the present embodiment, information on the blind spot of the potentiometer 75 (information indicating which region of the rotation position the blind spot is) is stored in the blind spot memory 63, and restrictions are made with reference to the blind spot memory 63. Thus, when the rotation position of the output gear 74 is a position within the blind spot of the potentiometer 75, rotation abnormality determination is not performed, and all rotation positions are set as rotation movable regions. In addition, in Figure 8 , the region between the rotation position of "300" and "360 (=0)" is the blind spot. Therefore, the position detectable region extends from the rotation position exceeding "0" to the rotation position of "300".

[0114] At the time of power-on startup, the fifth comparison unit 64 receives an instruction from the instruction unit 51A, compares the position information (ADC value) obtained from the AD converter 52 with a specified value defined as an abnormal value, and transmits the comparison result to the instruction unit 51A. The abnormal value is the value obtained from the AD converter 52 when the potentiometer 75 fails to obtain a value, and is a value indicating that the rotation position of the output gear 74 is within the blind spot of the potentiometer 75. For example, the position information obtained from the AD converter 52 is a value such as "0".

[0115] The instruction unit 51A determines whether the position information obtained from the AD converter 52 is an abnormal value based on the comparison result received from the fifth comparison unit 64. When the position information obtained from the AD converter 52 at the time of power-on is an abnormal value, the instruction unit 51A considers that the position information obtained from the AD converter 52 indicates that the rotational position of the output gear 74 is within the blind area of the potentiometer 75, and can notify the upper-level controller of the initial position abnormality. That is, the instruction unit 51A functions as an initial position abnormality determination unit, and when the position information obtained from the AD converter (an example of a position information acquisition unit) 52 at the time of power-on indicates that the rotational position of the output gear 74 is within the blind area of the potentiometer 75, it determines that there is an initial position abnormality and can notify the upper-level controller (an example of the outside) of the initial position abnormality.

[0116] The operation of the control device 10 of the rotating device 1 at the time of power-on in the above-described third embodiment will be described.

[0117] Figure 9 It is a flowchart showing the flow of the initial setting operation of the control device 10 of the rotating device 1 at the time of power-on, Figure 10 It is a flowchart showing the operation flow of the first drive command after the power-on of the control device 10 of the rotating device 1.

[0118] First, as Figure 9 shown, at the time of power-on of the control device 10 of the rotating device 1 (step S301), the AD converter 52 acquires the voltage (position information) corresponding to the rotational position input from the potentiometer 75 (step S302), and transmits the value after AD conversion (the ADC value at startup) as the initial position information to the fifth comparison unit 64 (step S303). The fifth comparison unit 64 compares the initial position information (the ADC value at startup) with the abnormal value (the value indicating that the rotational position of the output gear 74 is within the blind area of the potentiometer 75), and the instruction unit 51A receives the comparison result. The instruction unit 51A functions as an initial position abnormality determination unit and determines whether it is an abnormal value (step S304).

[0119] If the initial position information is not an abnormal value (step S304: NO), the instruction unit 51A records the position calculated based on the initial position information (the ADC value at startup) in the position memory 55 (step S305). On the other hand, if the initial position information is an abnormal value (step S304: YES), the instruction unit 51A notifies the outside such as the upper-level controller that the position information obtained at the time of power-on indicates that the rotational position of the output gear 74 is within the blind area of the potentiometer 75 (there is an initial position abnormality) (step S305).

[0120] Thus, when the position information obtained by the instruction unit 51A from the AD converter 52 at power-on indicates that the rotational position of the output gear 74 is within the blind area of the potentiometer 75, it can notify the higher-level controller of this meaning. Therefore, the higher-level controller can know that the instruction unit 51A fails to correctly obtain the position information from the AD converter 52 at power-on.

[0121] Next, as Figure 10 shown, when the instruction unit 51A receives the first drive instruction signal after power-on (step S401), it determines whether the ADC value at startup output from the AD converter 52 is abnormal (initial position abnormality) (step S402). If the ADC value at startup output from the AD converter 52 is not abnormal (step S402: No), the instruction unit 51A performs normal drive control based on the drive target included in the drive instruction signal (step S403). In normal drive control, in order to move to the drive target, drive control is performed by outputting drive pulses of the required number of pulses.

[0122] If the ADC value at startup output from the AD converter 52 is abnormal (step S402: Yes), then different from normal drive control, the instruction unit 51A uses the potentiometer 75 (position sensor) to move the rotational position of the stepping motor 20 (step S404). Specifically, in the process of step S404, the drive pulse output unit 61 outputs drive pulses until the ADC value output from the AD converter 52 becomes a non-abnormal value, thereby moving the rotational position of the stepping motor 20. At this time, the stepping motor 20 rotates until the rotational position of the output gear 74 is within the position detectable area of the potentiometer 75. That is, when the instruction unit 51A receives the first drive instruction signal after power-on when it determines that the initial position is abnormal, the drive pulse output unit 61 outputs drive pulses until the AD converter 52 can obtain the position information based on the rotational position read by the potentiometer 75 instead of outputting the number of drive pulses corresponding to the drive target included in the drive instruction signal.

[0123] If the rotational position of the output gear 74 rotates to the position detectable area of the potentiometer 75, the abnormality of the ADC value at startup is reset (step S405). At this time, the instruction unit 51A can record the position calculated based on the ADC value output from the AD converter 52 after moving to the position detectable area of the potentiometer 75 as the current rotational position of the output gear 74 in the position memory 55. After being recorded in the position memory 55, normal drive operations can be performed.

[0124] Thus, even when the position information output from the AD converter 52 at the time of power-on indicates that the rotational position of the output gear 74 is within the blind area of the potentiometer 75, the instruction unit 51A can, based on the drive instruction signal, move the rotational position of the output gear 74 to the position detectable area of the potentiometer 75 to obtain the position information, and then perform a normal drive operation. That is, even when the drive is performed based on a drive target corresponding to the blind area of the potentiometer 75 before power-on (the rotational position of the output gear 74 at the time of power-on is within the blind area of the potentiometer 75), the drive operation can be started without problems, and thus the rotational positions corresponding to the blind area of the potentiometer 75 can also be included in the rotation movable area.

[0125] Next, the operation of the control device 10 of the rotating device 1 according to the third embodiment described above will be described.

[0126] Figure 11 It is a flowchart for explaining the operation of the control device 10 of the rotating device 1 according to the third embodiment. In the control device 10 of the rotating device 1 according to the present embodiment, the instruction unit 51A receives a drive instruction signal (command) from the upper controller (step S501), and thus starts Figure 11 the operation.

[0127] In addition, the control method of the rotating device 1 according to the present embodiment includes: a drive pulse output step in which drive pulses corresponding to the number of times corresponding to the drive target are repeatedly output to the drive circuit 40 that applies a drive voltage to the stepping motor 20 that rotates the output gear 74 of the rotating device 1; a position information acquisition step in which position information is acquired from the potentiometer 75 that reads the rotational position of the output gear 74 at a specified repetition time in the drive pulse output step; a blind area determination step in which it is determined whether the rotational position of the output gear 74 after rotation by the stepping motor 20 is a position within the blind area of the potentiometer 75 where the rotational position cannot be read by the potentiometer 75; and a rotation abnormality determination step in which only when it is determined in the blind area determination step that the rotational position of the output gear 74 is not a position within the blind area of the potentiometer 75, it is determined whether the rotating device 1 has a rotation abnormality based on the position information acquired in the position information acquisition step.

[0128] When the instruction unit 51A receives a drive instruction signal from the upper controller, first, prior to the drive pulse emission process, various setting operations for appropriately performing the rotation abnormality determination are performed. Specifically, the instruction unit 51A calls the number of turns count value Z from the position memory 55 (step S502), calls the position count value Co (step S503), and recalculates the current position of the output gear 74 (step S504). The recalculation of the current position Cp can be calculated by the position count value Co + 360 × the number of turns count value Z.

[0129] Thereafter, the instruction unit 51A instructs the AD converter 52 to acquire the position information read by the current potentiometer 75. The AD converter 52 acquires the position information A (an example of the first position information) read by the potentiometer 75 as a reference position, and stores the acquired position information A in the A memory 53 (step S505). In addition, at the time of step S505, the N counter 56 receives a reset instruction from the instruction unit 51A, and resets the value of the N counter to 0.

[0130] Following step S505, the drive pulse output unit 61 receives an emission instruction for output pulses from the instruction unit 51A, and emits drive pulses to the motor drive unit 41 of the drive circuit 40 (step S506; drive pulse output step). Thereby, the stepping motor 20 is driven and controlled by applying a drive voltage to the motor drive unit 41.

[0131] Following step S506, the pulse counter 54 receives a counting instruction for output pulses from the instruction unit 51A, increments the counter (step S507), and transfers the incremented pulse count value to the position memory 55 and the revolution counter 65.

[0132] The revolution counter 65 refers to the current rotational position (position count value) of the output gear 74 stored in the position memory 55, adds the pulse count value received from the pulse counter 54 to the position count value, and thereby determines whether the brush of the potentiometer 75 has crossed the boundary line (reference position) of one revolution (step S508). When the brush of the potentiometer 75 has crossed the boundary line (step S508: YES), it further determines whether the rotational direction of the potentiometer 75 is the forward direction (step S509). When it is determined that the rotational direction of the potentiometer 75 is the forward direction (step S509: YES), the revolution counter 65 increments the revolution count value Z by "1" (step S511). When it is determined that the rotational direction of the potentiometer 75 is the reverse direction (step S509: NO), the revolution counter 65 decrements the revolution count value Z by "1" (step S512), and transfers the revolution count value to the position memory 55.

[0133] When receiving the incremented pulse count value and the revolution count value, the position memory 55 updates the current position (position count value) of the output gear 74 based on the position recalculated in step S504, the received pulse count value, and the revolution count value (step S513). Thereby, the position count value is updated until it becomes the drive target (target count value).

[0134] After step S513, the N-counter 56 receives a counting instruction for the N-counter from the instruction unit 51A and increments the N-counter value (step S514; position information acquisition step). Thus, the N-counter value reflects the number of drive pulses emitted for each prescribed rotational abnormality determination interval.

[0135] After step S514, the first comparison unit 57 receives a comparison instruction from the instruction unit 51A, compares the N-counter value of the N-counter 56 with the X value held in the X memory 58 (determines whether N-counter value > X value) (step S515), and passes the comparison result to the instruction unit 51A. Thus, the X value, which is the reference for the timing of determining the rotational abnormality of the rotating device 1, is compared with the N-counter value that reflects the number of drive pulses emitted, so that it is possible to determine the timing of the rotational abnormality determination to be performed at each prescribed rotational abnormality determination interval.

[0136] When the instruction unit 51A receives the comparison result that the N-counter value is greater than the X value (step S515: YES), it determines that it is a prescribed rotational abnormality determination interval. Furthermore, based on the comparison result received from the fourth comparison unit 62, it determines whether the rotational position of the output gear 74 is a position within the blind area of the potentiometer 75 (step S516; blind area determination step). When it is determined that the rotational position of the output gear 74 is not a position within the blind area of the potentiometer 75 (step S516: NO), it executes the rotational abnormality determination process. Specifically, the instruction unit 51A requests the AD converter 52 to acquire the current position information and issues a comparison instruction to the second comparison unit 59. When the second comparison unit 59 receives the comparison instruction from the instruction unit 51A, it acquires the position information A stored in the A memory 53 and the current position information (an example of the second position information) B acquired by the AD converter 52 (step S517). After step S517, the second comparison unit 59 calculates the difference D (= B - A or = A - B) between the position information A and the position information B, and compares the calculated difference D with the values ((C - α) and (C + α)) obtained by adjusting the previously held ideal difference C by the allowable value α (step S518; rotational abnormality determination step), and passes the comparison result to the instruction unit 51A. In addition, the allowable value α can be set to any value. Also, the absolute values of -α and +α can be set to different values. Furthermore, the ideal difference C is a value determined by multiplying the change amount of the rotational position per unit drive pulse by the number of drive pulses output during the period from the execution of the previous rotational abnormality determination process to the execution of the current rotational abnormality determination process.

[0137] When the instruction unit 51A obtains a comparison result indicating that the calculated difference D is outside the range of the value obtained by adjusting the ideal difference C by the allowable value α (i.e., (C - α) < D < (C + α) is not satisfied) (step S518: No), it determines that the rotation device 1 has a rotation abnormality, sets the error flag (step S519), and stops the output of the drive pulse to the drive pulse output unit 61. As a result, the drive of the stepping motor 20 stops (step S520). In addition, the process of setting the error flag in step S519 can also be omitted.

[0138] Here, use Figure 5 to further explain the rotation abnormality determination process. Figure 5 is a diagram for explaining the rotation abnormality determination. In Figure 5 the example, it is described with the case where the number of command pulses for one drive of the stepping motor 20 output according to the drive command signal is 20 pulses, the specified rotation abnormality determination interval of the pulses is 10 pulses (i.e., the X value is 9), and the allowable value is α. In addition, this example only shows an example of numerical values and is not limited thereto.

[0139] In Figure 5 it, the number of command pulses for the stepping motor 20 is shown on the horizontal axis, and the position sensor output value (the value of the position information output from the potentiometer 75) is shown on the vertical axis. In addition, along the horizontal axis, the determination counter N (N counter value), the rotation abnormality determination time, and the movement start time are shown. In this example, it can be seen that the N counter value is updated every 10 counts, and the determination time becomes every 10 pulses (counts). In addition, in this figure, it is shown that in the A memory 53, the position information A1, A2, A3 is stored as the first position information as the reference position. The position information B1, B2, B3 represents the ideal second position information corresponding to the position information A1, A2, A3, respectively.

[0140] In the control device 10 of the rotation device 1 of the present embodiment, during normal operation, as Figure 5 shown in the graph of the normal output value transition example, the output value (the value of the position information) of the potentiometer 75 increases in proportion to the increase in the number of drive pulses. However, if a rotation abnormality occurs, a value deviated from this graph is shown.

[0141] For example, it is described with the case where "Ba" and "Bb" are obtained as the current position information B at the determination time of the 30th step.

[0142] In this case, at the previous determination time of the determination time in step 30, in the A memory 53, the position information A3 is stored as the first position information as the reference position. Therefore, when "Ba" is obtained as the current position information (an example of the second position information) B, the difference D1 becomes Ba - A3. This difference D1 is within the range of the value obtained by adjusting the ideal difference C by the allowable value α. Therefore, in this case, it is not determined that there is a rotation abnormality.

[0143] On the other hand, when "Bb" is obtained as the current position information (an example of the second position information) B, the difference D2 becomes Bb - A3. This difference D2 is outside the range of the value obtained by adjusting the ideal difference C by the allowable value α. Therefore, in this case, it is considered that the position "B3" corresponding to the number of output pulses has not been reached, and a rotation abnormality is determined. That is, the instruction unit 51A functions as a rotation abnormality determination unit, and determines that a rotation abnormality has occurred in the rotation device when the difference D between the first position information last obtained by the AD converter (an example of the position information acquisition unit) 52 and the second position information currently obtained by the AD converter 52 is different from the ideal difference C by more than the allowable value α.

[0144] On the other hand, in Figure 11 In step S515, when the instruction unit 51A receives the comparison result that the N counter value is not greater than the X value (step S515: No), it can be determined that it is not the time for rotation abnormality determination. Similarly, when the instruction unit 51A determines, based on the comparison result received from the fourth comparison unit 62, that the rotation position of the output gear 74 is within the blind area of the potentiometer 75 (step S516: Yes), it can also be determined that it is not the time for rotation abnormality determination. In addition, when the instruction unit 51A obtains the comparison result that the calculated difference D is within the range of the value obtained by adjusting the ideal difference C by the allowable value α ((C - α) < D < (C + α)) (step S518: Yes), it can be determined that the result of the rotation abnormality determination is determined to be normal. In these cases (step S515: No, step S516: Yes, and step S518: Yes), the instruction unit 51A issues a comparison instruction to the third comparison unit 60 in order to determine the stop condition. When receiving the comparison instruction, the third comparison unit 60 compares the target count value with the position count value in order to determine whether to clear the stop condition (step S521), and transmits the comparison result to the instruction unit 51A.

[0145] When the instruction unit 51A receives the comparison result that the stop condition is cleared because the position count value has reached the target count value (step S521: Yes), it ends the emission of drive pulses (step S520).

[0146] When the instruction unit 51A receives the comparison result that the position count value has not reached the target count value and thus the stop condition has not been cleared (step S521: No), it determines whether it is the time for rotation abnormality determination based on whether the comparison result received in step S515 is N counter value > X value (step S522). When the determination result in step S522 is that it is determined to be the time for rotation abnormality determination (step S522: Yes), the instruction unit 51A returns to the process of step S503. When the determination result in step S522 is that it is determined not to be the time for rotation abnormality determination (step S522: No), the instruction unit 51A returns to the process of step S506.

[0147] According to the control device, rotating device, and control method of the rotating device of the present embodiment, the rotation position of the stepping motor has been controlled by open-loop control based on a drive instruction signal as in the past. That is, the position information obtained by the position sensor is not used as the position information in normal motor drive, so the position accuracy and high resolution in the existing stepping motor are not impaired. On the other hand, as long as the position information can discriminate the degree to which the output gear physically moves, there is no need for high-precision position detection like a position sensor for normal position detection, and a low-cost position sensor with relatively coarse accuracy can be used, so it can be implemented at low cost.

[0148] In addition, even if there is a blind spot within one revolution of the position sensor where position information cannot be obtained, all the rotational positions of the position sensor and rotational positions exceeding one revolution (360 degrees) can be included in the movable area. Therefore, compared with the existing rotating device, the movable area can also be expanded.

[0149] (Fourth Embodiment)

[0150] Next, the control device, rotating device, and control method of the rotating device of the fourth embodiment will be described. In the third embodiment, the instruction unit 51A performs rotation abnormality determination at a prescribed rotation abnormality determination interval, but in this embodiment, the instruction unit 51A performs driving until the drive target (stop condition cleared) is reached and then performs rotation abnormality determination, which is different in this regard. In the fourth embodiment, for the components other than the instruction unit 51A, a control device and a rotating device of the rotating device having the same configuration as that of the third embodiment can be adopted. For the fourth embodiment, only the configuration different from that of the third embodiment will be described, and the description of the configuration common to the third embodiment will be omitted.

[0151] Figure 12 is a flowchart for explaining the operation of the control device 10 of the rotating device 1 of the fourth embodiment. Refer to Figure 7 and Figure 12The operation of the control device 10 of the rotation device 1 in the fourth embodiment will be described. In the control device 10 of the rotation device 1 in the fourth embodiment, from Figure 12 step S601 to step S613, the same processing as steps S501 to S513 in the third embodiment is performed. From Figure 12 step S618 to step S621, the same processing as steps S517 to S520 in the third embodiment is performed.

[0152] In the present embodiment, the processing from the emission of the drive pulse (step S606) to the update of the current position (step S613) is repeated until the stop condition is cleared (step S614: YES).

[0153] When the instruction unit 51A determines that the stop condition is cleared (step S614: YES), it stops the drive of the stepping motor 20 (step S615). Furthermore, the instruction unit 51A determines whether the rotational position of the output gear 74 is a position within the blind area of the potentiometer 75 based on the comparison result received from the fourth comparison unit 62 (step S616). When it is determined that the rotational position of the output gear 74 is not a position within the blind area of the potentiometer 75 (step S616: NO), it determines whether the determination condition is satisfied (step S617). Specifically, the first comparison unit 57 receives a comparison instruction from the instruction unit 51A, compares the N-counter value of the N-counter 56 with the X value of the X memory 58, and returns the comparison result to the instruction unit 51A. When the N-counter value is greater than the X value, the instruction unit 51A determines that the determination condition is satisfied. When the instruction unit 51A determines that the rotational position of the output gear 74 is a position within the blind area of the potentiometer 75 (step S616: YES), it does not execute the rotation abnormality determination process and ends the drive process.

[0154] In the present embodiment, in step S605, the position information at the start time of the output of the drive pulse is acquired, and the acquired position information (an example of the third position information) A is stored in the A memory 53 as the information of the reference position. Regarding the rotation abnormality determination process, in step S618, the position information (an example of the fourth position information) B at the end time of the output of the drive pulse is acquired. In step S619, the difference D from the position information A stored in the A memory 53 is calculated, and the rotation abnormality determination is performed by comparison.

[0155] In the present embodiment, when the number of drive pulses is too small, the accuracy of rotation abnormality determination decreases. Therefore, by determining whether to execute the process of rotation abnormality determination in step S617, it is possible to avoid a decrease in the accuracy of rotation abnormality determination. However, when the number of drive pulses for one drive of the stepping motor 20 output according to the drive instruction signal is large enough, the process of step S617 is not necessarily required. In this case, it is possible to omit Figure 7 the N counter 56, the first comparison unit 57, and the X memory 58 of the control device 10 shown.

[0156] In the above embodiment, Figures 1 to 3 , Figure 7 A specific example of the control method of the rotating device 1 having the configuration of is described. The control method of the rotating device 1 of the present embodiment may include the following steps, and is not limited to the specific embodiment, that is, it includes: a drive pulse output step in which a drive circuit 40 that applies a drive voltage to a stepping motor 20 that rotates an output gear of the rotating device 1 repeatedly outputs drive pulses corresponding to the number of times of the drive target; a position information acquisition step in which position information is acquired from a potentiometer 75 (an example of a position sensor) that reads the rotational position of the output gear 74 at a specified repetition time in the drive pulse output step; and a rotation abnormality determination step in which it is determined whether the rotating device 1 has a rotation abnormality based on the position information acquired in the position information acquisition step.

[0157] (Modification example of the embodiment)

[0158] In the above embodiment, the configuration of the control device 10 is not limited to Figure 1 the configuration, the configuration of the drive control unit 50 is not limited to Figure 2 the configuration, and the configuration of the rotating device is not limited to Figure 3 , 7 the configuration.

[0159] As a specific example, a modification example of the drive control unit in the third embodiment and the fourth embodiment is described. Figure 13 is a diagram showing a modification example of the configuration of the functional block implemented by the drive control unit 50B of the control circuit 30. In Figure 7 , instead of the fourth comparison unit 62 configured to be connected to the instruction unit 51A, as Figure 13As shown, by disposing a comparison determination unit 66 (an example of a rotation abnormality determination restriction unit) in front of the AD converter 52, it is also possible to restrict the rotation abnormality determination. In this case, when the rotational position of the output gear 74 after being driven by a drive pulse is a position within the blind area of the potentiometer 75 where the potentiometer 75 cannot read the rotational position, if the comparison determination unit 66 does not output a signal to the AD converter 52, the comparison process in the second comparison unit 59 cannot be substantially performed, and thus the execution of the rotation abnormality determination process can be restricted.

[0160] For example, in Figure 7 , instead of the blind area memory 63 that stores information on the blind area of the potentiometer 75, a memory that stores information on the position detectable area can be used. In this case, it is different from the process based on the determination result determined using the blind area memory 63 in the determination process of the fourth comparison unit 62. That is, the process when the determination result is Yes is opposite to the process when the determination result is No.

[0161] In the above-described embodiments, Figure 4 , 6 , the processing flows shown in FIGS. 9 to 12 are merely specific examples, and the processing flow is not limited thereto.

[0162] In addition, although the potentiometer 75 is exemplified as a unit for reading position information in the above-described embodiments, it is not limited thereto, and as long as it is a position sensor that physically reads the rotational position of the gear, it can also be a magnetic sensor or the like, for example.

[0163] Description of Reference Numerals

[0164] 1... Rotating device, 10... Control device, 11... Control substrate, 12... Housing, 20... Stepper motor, 30... Control circuit, 40... Drive circuit, 41... Motor drive unit, 50, 50A, 50B... Drive control unit, 51, 51A... Instruction unit (an example of rotation abnormality determination unit, rotation abnormality determination restriction unit, initial position abnormality determination unit), 52... AD converter (an example of position information acquisition unit), 53... A memory, 54... Pulse counter, 55... Position memory, 56... N counter, 57... First comparison unit, 58... X memory, 59... Second comparison unit, 60... Third comparison unit, 61... Drive pulse output unit, 62... Fourth comparison unit, 63... Blind area memory, 64... Fifth comparison unit, 65... Revolution counter, 66... Comparison determination unit (an example of rotation abnormality determination restriction unit), 70... Actuator output shaft, 71... First gear, 72... Second gear, 73... Third gear, 74... Output gear, 75... Potentiometer (an example of position sensor), 76... FPC, A, A1, A2, A3... Position information (an example of first position information, third position information), B, B1, B2, B3, Ba, Bb... Position information (an example of second position information, fourth position information).

Claims

1. A control device for a rotating device, characterized in that, it comprises: a drive circuit that applies a drive voltage to a stepping motor that rotates an output gear of the rotating device; and a control circuit that outputs a number of drive pulses corresponding to a drive target contained in a drive instruction signal from the outside to the drive circuit, the control circuit having: a drive pulse output unit that outputs a number of drive pulses corresponding to a drive target contained in the drive instruction signal; a position information acquisition unit that acquires position information from a position sensor that reads the rotational position of the output gear of the rotating device; and a rotation abnormality determination unit that determines whether the rotating device has a rotation abnormality based on the position information acquired by the position information acquisition unit, whenever the number of drive pulses output by the drive pulse output unit reaches a specified value, the position information acquisition unit acquires position information from a position sensor that reads the rotational position of the output gear of the rotating device, when the difference D between the first position information last acquired by the position information acquisition unit and the second position information currently acquired by the position information acquisition unit differs from the ideal difference C by more than an allowable value α, the rotation abnormality determination unit determines that the rotating device has a rotation abnormality.

2. The control device for a rotating device according to claim 1, wherein, the control circuit has: a first counter that counts the number of drive pulses output by the drive pulse output unit; a first memory that stores the specified value; a comparator that compares the value counted by the first counter with the specified value stored in the first memory; and an instruction unit that, when the result of the comparison by the comparator is that the counted value is greater than the specified value, determines that the number of drive pulses has reached the specified value and issues instructions to each part of the control circuit.

3. A control device for a rotating device, characterized in that, it comprises: a drive circuit that applies a drive voltage to a stepping motor that rotates an output gear of the rotating device; and a control circuit that outputs a number of drive pulses corresponding to a drive target contained in a drive instruction signal from the outside to the drive circuit, the control circuit having: a drive pulse output unit that outputs a number of drive pulses corresponding to a drive target contained in the drive instruction signal; a position information acquisition unit that acquires position information from a position sensor that reads the rotational position of the output gear of the rotating device; and a rotation abnormality determination unit that determines whether the rotating device has a rotation abnormality based on the position information acquired by the position information acquisition unit, at each moment when the drive pulse output unit starts and ends the output of the drive pulses, the position information acquisition unit acquires position information from a position sensor that reads the rotational position of the output gear of the rotating device, When the difference D between the third position information acquired by the position information acquisition unit at the moment of starting the output of the drive pulse and the fourth position information acquired by the position information acquisition unit at the moment of ending the output of the drive pulse differs from the ideal difference C by more than the allowable value α, the rotation abnormality determination unit determines that a rotation abnormality has occurred in the rotating device.

4. The control device for a rotating device according to claim 1 or 3, wherein, the control circuit further has an output stop unit that stops the output of the drive pulse in the drive pulse output unit when the rotation abnormality determination unit determines that a rotation abnormality has occurred in the rotating device.

5. The control device for a rotating device according to claim 1 or 3, wherein, the position sensor is a potentiometer that outputs a voltage corresponding to the rotation position as position information.

6. A control device for a rotating device, characterized in that, it includes: a drive circuit that applies a drive voltage to a stepping motor that rotates an output gear of the rotating device; and a control circuit that outputs a number of drive pulses corresponding to a drive target included in a drive instruction signal from the outside to the drive circuit, the control circuit has: a drive pulse output unit that outputs a number of drive pulses corresponding to a drive target included in the drive instruction signal; a position information acquisition unit that acquires position information from a position sensor that reads the rotation position of the output gear of the rotating device; and a rotation abnormality determination unit that determines whether a rotation abnormality has occurred in the rotating device based on the position information acquired by the position information acquisition unit, the control device for the rotating device has a rotation abnormality determination restriction unit that restricts the determination in the rotation abnormality determination unit from being executed when the rotation position of the output gear driven by the drive pulse is a position within a blind area where the position sensor cannot read the rotation position.

7. The control device for a rotating device according to claim 6, wherein, the control circuit further has an initial position abnormality determination unit that determines an initial position abnormality when the position information acquired from the position information acquisition unit at the time of power-on startup indicates that the rotation position of the output gear is a position within the blind area of the position sensor, the control circuit notifies the outside of the initial position abnormality determined by the initial position abnormality determination unit.

8. The control device for a rotating device according to claim 7, wherein, when the control circuit receives the first drive instruction signal after power-on startup after the initial position abnormality determination unit determines an initial position abnormality, the drive pulse output unit does not output a number of drive pulses corresponding to the drive target included in the drive instruction signal, but outputs drive pulses until the position information acquisition unit can acquire position information based on the rotation position read by the position sensor.

9. The control device for a rotating device according to claim 6, wherein, the control device for the rotating device includes: a position memory storing a current position consisting of a combination of a rotational position of an output gear of the rotating device and a rotational speed of the output gear of the rotating device; a pulse counter that counts the number of drive pulses output by the drive pulse output unit and outputs a pulse count value; as well as a turn counter that outputs a turn count value obtained by counting the number of times a drive pulse corresponding to the pulse count value passes through a reference position within one turn of the position sensor in a positive direction from a current position of the position memory, The current position of the position memory is updated by using the pulse count value and the turn count value.

10. The control device for the rotating device according to claim 9, in, The turn counter counts down the turn count value when the position sensor passes through a reference position within one turn in the reverse direction.

11. A rotating device, It is characterized in that have: A stepping motor, which is rotationally driven by the control device of the rotating device according to any one of claims 1, 3 and 6; an output gear that rotates in conjunction with the rotational movement of the stepper motor; and A position sensor detects the rotational position of the output gear.

12. A method for controlling a rotating device, It is characterized in that include: a driving pulse outputting step, wherein a driving circuit for applying a driving voltage to a stepping motor repeatedly outputs driving pulses a number of times corresponding to a driving target, and the stepping motor rotates an output gear of the rotating device; a position information acquiring step, wherein, at a predetermined repetition timing of the drive pulse outputting step, position information is acquired from a position sensor that reads a rotational position of an output gear of the rotating device; and a rotation abnormality determination step, wherein, based on the position information acquired in the position information acquisition step, it is determined whether the rotation device has a rotation abnormality, Whenever the number of drive pulses outputted by the drive pulse outputting step reaches a predetermined value, in the position information acquiring step, position information is acquired from a position sensor that reads the rotational position of the output gear of the rotating device, When the difference D between the first position information acquired last by the position information acquisition step and the second position information acquired this time by the position information acquisition step differs from the ideal difference C by more than the allowable value α, in the rotation abnormality determination step, it is determined that the rotating device has a rotation abnormality.

13. A method for controlling a rotating device, It is characterized in that include: a driving pulse outputting step, wherein a driving circuit for applying a driving voltage to a stepping motor repeatedly outputs driving pulses a number of times corresponding to a driving target, and the stepping motor rotates an output gear of the rotating device; a position information acquiring step, wherein, at a predetermined repetition timing of the drive pulse outputting step, position information is acquired from a position sensor that reads a rotational position of an output gear of the rotating device; and Rotation abnormality determination step, wherein, based on the position information obtained in the position information acquisition step, it is determined whether the rotation device has a rotation abnormality. In the position information acquisition step, at each moment when the output of the drive pulse starts and ends in the drive pulse output step, position information is obtained from a position sensor that reads the rotation position of the output gear of the rotation device. When the difference D between the third position information obtained by the position information acquisition step at the moment when the output of the drive pulse starts and the fourth position information obtained by the position information acquisition step at the moment when the output of the drive pulse ends differs from the ideal difference C by more than the tolerance value α, in the rotation abnormality determination step, it is determined that the rotation device has a rotation abnormality.

14. A control method for a rotation device Characterized in that It includes: A drive pulse output step, wherein a drive circuit that applies a drive voltage to a stepping motor repeatedly outputs drive pulses corresponding to the number of times of the drive target, and the stepping motor rotates the output gear of the rotation device; A position information acquisition step, wherein at a specified repetition moment of the drive pulse output step, position information is obtained from a position sensor that reads the rotation position of the output gear of the rotation device; and A rotation abnormality determination step, wherein, based on the position information obtained in the position information acquisition step, it is determined whether the rotation device has a rotation abnormality. After the position information acquisition step, it further includes a blind area determination step, in which it is determined whether the rotation position of the output gear driven by the drive pulse is a position within the blind area of the position sensor where the rotation position cannot be read by the position sensor. Only when it is determined in the blind area determination step that the rotation position of the output gear is not a position within the blind area of the position sensor, the rotation abnormality determination step is executed.

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