JP5622532B2 - Motor system - Google Patents

Description

  The present invention relates to a mechanism that moves by a motor output and detects a stop position by a detector, for example, a motor controller of a disk rotation mechanism that lays a reagent or a specimen, etc., and particularly has a correlation with a physical arrangement with respect to the erection position. The present invention relates to a motor system that performs stop control at a predetermined position by counting a change in signal detected by a detector.

  Patented technology for stopping a disk at a predetermined position using a signal change detected by a detector with a detector to detect a detected object having a correlation between the mounting position and a physical arrangement on a disk on which a reagent or specimen is installed. It is described in Document 1.

  In the above-described technique, in the motor controller that controls the rotation and stop operation of the disk on which the reagent or the specimen is installed, the disk rotation mechanism is provided with at least one object to be detected although there is a correlation between the installation position and the physical arrangement, The disk is stopped at a predetermined position by counting the number of signal changes when the detector detects the object to be detected.

JP 2000-346853 A

  When a disk on which a reagent or sample is installed is rotated by a motor, vibration may occur in the rotation of the disk, particularly at a low speed, due to the relationship between the rotational speed and the mechanical resonance frequency of the disk. In addition, foreign matter such as dust and condensed water may adhere to the detection object installed on the disk. In addition, electrical noise may be superimposed on the detector output signal.

  These are unintended signal changes of the output signal from the detector when the disk rotates, and if the signal change is counted by the motor controller, the signal change count becomes larger than the original count, which may cause the disc stop position shift. Become.

  An object of the present invention is to stop a disk at a predetermined position even when an unintended signal change occurs from a detector when the disk rotates.

  The configuration of the present invention for achieving the above object is as follows.

  A filter circuit whose filter characteristics can be changed to an input circuit of a counter that counts signal changes by a motor controller in response to an output signal from a detector when a disk on which a reagent or specimen is mounted is rotated, and the input signal is monitored And a control circuit for performing processing in the motor controller according to the report of the monitoring circuit.

  In such a motor controller input circuit, when the period of the signal change from the detector is shorter than the set value of the filter circuit when the disk rotates, the signal change is counted by the motor controller to be removed by the filter. do not do.

  In addition, the monitoring circuit monitors whether the input signal has changed again at a set time after the input signal has changed, and if the input signal changes again, the monitoring circuit sets the first signal change to the control circuit as an abnormal signal. Report. When the control circuit receives an abnormality report from the monitoring circuit, the control circuit performs processing to restore the counter that counts the change in the input signal. Alternatively, the control circuit holds the count of signal change until the set time of the monitoring circuit elapses from the change of the input signal, and counts when there is no abnormality report from the monitoring circuit.

  According to the present invention, an unintended signal of the output signal from the detector when the disc rotates due to vibration of the disc rotation, adhesion of foreign matter to the detected object, or superimposition of noise on the output signal of the detector, etc. Even if a change occurs, the disk can be stopped at a predetermined position.

Schematic of a disk rotation mechanism. Detector output signal during disk rotation. Signal after filtering. Motor controller internal block diagram. Schematic of a motor controller internal filtering process. The motor controller internal filter circuit control flowchart. The motor controller internal monitoring circuit control flowchart. Schematic of a motor controller internal monitoring process. Schematic of a stage mechanism. Schematic of origin detection timing.

  Embodiment 1 of the present invention will be described below with reference to FIGS.

  1 is a schematic diagram of a disk rotation mechanism to which the present invention is applied, FIG. 2 is an output signal from a detector during disk rotation, FIG. 3 is a filtered signal, FIG. 4 is an internal block diagram of a motor controller, and FIG. FIG. 6 is a control flowchart of a filter circuit in the motor controller.

  In FIG. 1, the motor controller 6 outputs a control pulse 7 to the motor driver circuit 5 based on information given from the user interface 11. As a result, the motor 4 rotates and the disk 1 rotates. When the disk 1 rotates, the detection object 2 corresponding to the stop position of the disk passes through the detector 3. When the detected object 2 passes through the detector 3, a detection signal 8 is output. The motor controller 6 counts the number of signal changes of the detection signal 8. At this time, since the signal change of the detection signal 8 occurs every time the detected object 2 passes the detector 3, the movement angle of the detected object 2 and further the movement angle of the installation position 10 are known from the signal change count. Can do. When this count reaches the specified number of times, the motor controller 6 outputs a correction pulse 12 given in advance from the user interface 11 in order to correct the installation position 10 and the absolute position of the detected object 2 corresponding thereto, and stops. As a result, the disk 1 stops at a predetermined position.

  The output signal from the detector during disk rotation will be described with reference to FIG. FIG. 2A shows the output state of the output signal of the detector 3, the signal change counter, and the control pulse 7 when the installation position, that is, the detected object 2 is moved to the N position.

  First, the number of movements of the body 2 to be detected, that is, the position of the installation position 10 can be grasped by counting until the change in the output signal from the detector reaches the specified number of times (N). Thereafter, when the change of the output signal 7 reaches the specified number of times, the correction pulse 12 for correcting the absolute position of the detected object 2 and the installation position 10 is output and stopped, thereby rotating the disk to a predetermined position.

  On the other hand, FIG. 2B is superimposed on the unintended detection signal 13 due to the foreign matter adhering to the detected object 2 and the detection signal 8 of the detector 3 when the same control pulse 7 as in FIG. This is a change in the count when the noise 14 and the chattering 15 due to the vibration during the disk rotation occur. When such an abnormal signal is superimposed, the signal change count in the motor controller is increased. For example, in FIG. 2B, when the signal change is to be stopped at a specified number of times (N) as in FIG. 2A. It will stop before this from Fig.2 (a), and will cause a stop position shift as a result.

  On the other hand, in order to remove the abnormal signal, when the filter circuit 9 is provided between the detector 3 and the motor controller 6 in FIG. 1, the output signal of the filter circuit 9, that is, the input signal to the motor controller 6 is obtained. This is described in FIG.

  3A, the noise 14 is superimposed on the detection signal 8 of the detector 3 as shown in FIG. 3B, and the chattering 15 due to vibration during disk rotation. Describes the case where this occurs. In this case, even if the time constant of the filter circuit 9 is small, the noise 14 superimposed on the output signal of the detector as shown in FIG. 3C, or the chattering 15 due to the rotational vibration due to the rotational speed of the disk, etc. The signal can be removed.

  However, the influence of an abnormal signal having a low frequency cannot be completely removed, such as the unintended detection signal 13 due to the foreign matter attached to the detected object in FIG.

  On the other hand, if the time constant of the filter circuit 9 is increased, the abnormal signal can be removed as shown in FIG. 3D, but the change in the output signal of the detector itself is delayed and exceeds the predetermined stop position. .

  Therefore, a method of mounting the function of the filter circuit 9 in the motor controller and changing the time constant of the filter circuit 9 according to the rotation state of the motor will be described with reference to FIGS.

  First, in FIG. 4, the detection signal 8 from the detector is filtered by the filter circuit 21. The signal filtered by the filter circuit 21 is input to the control circuit 23, and the output change counter 24 is updated when the signal changes. Further, the control circuit 23 switches the setting of the time constant of the filter circuit 21 based on the information of the output change counter 24. For example, the operation of the control circuit 23 will be specifically described when a detection signal 8 as shown in FIG. 5A is input to the motor controller 6 from the detector.

  In order to stop the disk at a predetermined position, only the signal change of the detection signal 27 of the detection target is counted, and the final count at which the output change counter 24 reaches the specified number of times is based on the detection signal 27 of the detection target. It is necessary to minimize the delay time until the signal change and the signal change are input to the control circuit 23. That is, it is only necessary to know the presence or absence of the detection signal 27 of the detected object at the detection time A in FIG. 5A, and at the detection time B, it is important to minimize the time constant of the filter circuit 21.

  Therefore, the time constant of the filter circuit 21 is increased until the count of the output change counter 24 is one time before the specified number of times as in the operation flowchart of FIG. The time constant of the filter circuit 21 is set to the minimum necessary value. In other words, by setting the detection time A to a time constant that is slightly shorter than the detection time of the detection signal 27 of the detection target, it is possible to remove even abnormal signals having a longer cycle.

  The output signal of the filter circuit 21 when the control of FIG. 6 is performed is as shown in FIG. In FIG. 5 (b), the unintended detection signal 13 due to the foreign matter adhering to the detected object, the noise 14 superimposed on the output signal of the detector, and the chattering 15 due to vibration during disk rotation are removed, and the final count is obtained. The delay time can be shortened compared with other counts.

  However, even when the filter output as shown in FIG. 5B is obtained in the first embodiment, the stop position shifts from the predetermined position by the amount of the pulse 31 output during the delay time due to the time constant of the filter circuit 21 in the final count. Will occur.

  Therefore, as another embodiment, a second embodiment using the monitoring circuit 22 for monitoring the output of the filter circuit 21 in FIG. 4 will be described below with reference to FIGS. 4, 7 and 8.

  In the signal change 32 and the signal change 33 in FIG. 8, when the signal change 32 is a signal change due to the detected object 2, the filter circuit 21 is used at the detection time B in the first embodiment without using the monitoring circuit 22. The signal change 32 may be counted by setting the constant to 0, that is, disabling the filter circuit 21.

  On the other hand, when the signal change 33 is a signal change due to the original object 2 to be detected, the filter circuit 21 is disabled and the monitor circuit 22 is enabled at the detection time B, and the detection signal 8 of the detector 3 is sent to the monitor circuit 22. Monitoring is performed according to the flowchart of FIG.

  First, it is the same as in the first embodiment until the count of the output change counter 24 is one time before the specified number of times, and the filter circuit 21 is disabled (time constant is 0) at the timing when it reaches one time before the specified number of times. The circuit 22 is enabled.

  When the monitoring circuit 22 detects the signal change 32 of the detection signal 8, the monitoring of the output signal is started and the correction pulse counter 26 starts counting the correction pulse. Further, the control circuit 23 puts the count of the signal change 32 on the output change counter 24 on hold.

  As shown in FIG. 8, the detector output signal 8 is monitored during the monitoring time 34 set by the control circuit 23, but the signal change 35 is detected by the monitoring circuit 22 during the monitoring time 34. Reports the signal change 32 as an abnormal signal from the monitoring circuit 22 to the control circuit 23. The control circuit 23 clears the correction pulse counter 26 while processing the output change count that has been put on hold as invalid.

  Further, when the monitoring circuit 22 detects the signal change 33, the same processing as described above starts. When no signal change occurs during the monitoring time 34 after the signal change 33 is detected by the monitoring circuit 22, the signal change 33 is reported as a normal signal from the monitoring circuit 22 to the control circuit 23. In the control circuit 23, the count of the signal change 33 that has been put on hold is validated and the output change counter 24 is updated. Thereafter, when the correction pulse counter 26 reaches the specified value, the pulse output is stopped.

  In the output signal processing of the detector as described above, even if an abnormal signal is superimposed on the output signal, the influence can be removed and the disk can be stopped at a predetermined position.

  Another embodiment using the motor system will be described with reference to FIGS. FIG. 9 is a schematic diagram of the stage control mechanism, and FIG. 10 is a schematic diagram of the origin detection timing. In FIG. 9, the X stage 36 is controlled by an X stage control motor 40 controlled by a motor controller 42, and its position is controlled by the number of moving pulses from the origin based on the detection information of the origin detector 39.

  Further, when the X stage 36 moves from the stop position (A) 37 and the stop position (B) 38 to the origin, the movement speed, that is, the rotation speed of the X stage drive motor 40 is increased as the movement distance is longer in order to shorten the movement time. Make it faster. At this time, when the X stage 36 reaches the origin detector 39, the output signal of the origin detector changes as shown in FIG. Thereafter, the output signal of the origin detector is filtered by the filter circuit 43 and transmitted to the motor controller 42 as an origin detection signal.

  At this time, if the time constant 44 of the filter circuit 43 is a constant value, a delay of the time constant 44 occurs between the detector detection timing 45 and the motor controller detection timing 46 as shown in FIG. If they are different, a difference occurs in the moving distance of the X stage during this delay time. That is, when the moving speed of the X stage 36 is different, an error occurs in the stop position of the X stage, resulting in an error in the position control of the X stage.

  Therefore, by changing the time constant of the filter circuit according to the moving speed of the X stage 36, that is, the rotational speed of the motor controller 42, the error of the moving distance of the time constant 44 can be reduced.

DESCRIPTION OF SYMBOLS 1 Disc 2 Detected object 3 Detector 4 Motor 5 Motor driver circuit 6 Motor controller 7 Control pulse 8 Detection signal 9 External filter circuit 10 Installation position 11 User interface 12 Stop position correction pulse 13 Detection signal 14 Foreign matter attached to the detected object Unintentional detection signal 15 due to disc rotation vibration 21 Filter circuit 22 Monitoring circuit 23 Control circuit 24 Output change counter 25 Pulse generation circuit 26 Stop position correction pulse counter 27 Detection signal 31 of detected object During delay time by filter circuit Output pulses 32, 33 Signal change 34 Monitoring time 35 Re-change signal 36 X stage 37 Stop position (A)
38 Stop position (B)
39 Origin detector 40 X stage drive motor 41 X stage drive motor driver 42 Motor controller 43 Filter circuit 44 Filter time constant 45 Detector detection timing 46 Motor controller detection timing

Claims (5)

A motor that generates a rotational motion by electrical energy;
A detector for detecting the rotational position of the motor;
In a motor system comprising: a motor controller that controls the rotation operation of the motor based on an output signal of the detector;
A filter that processes the output signal of the detector, and a control mechanism that changes a time constant of the filter in accordance with the rotational speed of the motor;
The motor controller counts the number of signal changes of the output signal, and when the counted number reaches a specified number, stops the motor,
The motor mechanism is characterized in that the control mechanism changes the time constant to a short time constant at a timing reached one time before the specified number of times . The motor system according to claim 1,
The motor system according to claim 1, wherein the motor is a stepping motor. The motor system according to claim 1 or 2,
The motor rotates a reaction disk in which a plurality of reaction vessels for reacting a sample and a reagent are arranged in a row,
The motor system comprising a detector plate that rotates integrally with the disk and a detector that detects the detector plate. The motor system according to claim 1,
A motor system comprising a control mechanism for changing a time constant of the filter in accordance with a rotational speed of the motor. The motor system according to claim 1,
And a monitoring circuit that starts monitoring the output signal at a timing reached one time before the specified number of times,
The motor controller outputs a correction pulse for correcting the stop position when the count reaches the specified number of times,
The control mechanism starts counting the correction pulse when monitoring of the monitoring circuit is started. When the signal change is detected during the monitoring time of the monitoring circuit, the control mechanism counts the correction pulse. A motor system characterized by clearing .

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