Method for servo drive, servo system and sensor identification processing

Abstract

A servo driver configured to drive a first motor and communicably connected to other servo drivers, configured to receive a detection signal from a first sensor that detects a parameter related to displacement of a first driven object driven via an output shaft of the first motor. Further, the servo driver, in a state in which sensor identification processing is not completed, identifies the first sensor as a first corresponding sensor associated with the servo driver when the detection signal is received from the first sensor in a case in which a first prescribed operation is performed in which only the output shaft of the first motor is driven to cause displacement of the first driven object.

Description

Technical Field

[0001] This invention relates to servo drives, servo systems, and methods for sensor identification and processing. Background Technology

[0002] In servo systems, servo drives typically perform servo control of servo motors according to instructions from controllers such as PLCs. In this servo control, sometimes the detection signals from external sensors other than the encoder built into the servo motor are utilized. Examples of external sensors include limit sensors that detect specific positions of the driven object by the motor. Conventionally, such external sensors are connected to the servo drive via sensor cables. However, in applications where servo systems are used, the servo drive is sometimes located far from the servo motor due to layout considerations. In such cases, the cable connecting the servo drive and the servo motor needs to be relatively long. Furthermore, the external sensor used to detect the motion of the driven object must be placed near the driven object.

[0003] If the distance between the servo motor and the servo driver is long, the sensor cable connecting the sensor and the servo driver also becomes longer. This increased cable length leads to problems such as the need for extensive labor and time for wiring work (e.g., connecting or routing the sensor cable). Therefore, Patent Document 1 discloses a technique where the sensor is connected to an encoder of the servo motor located near the sensor via a cable, and the sensor's detection signal and the feedback signal generated by the encoder are transmitted from the encoder to the servo driver. According to this technique, by connecting the sensor to the encoder, the sensor's detection signal can be transmitted to the servo driver, thereby preventing the cable length between the sensor and the servo driver from increasing.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 6349687 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] According to existing technology, in order to input the detection signal of the sensor used by the servo drive to the servo drive side, wiring is installed between the sensor and the encoder. In this case, if the servo system includes multiple servo drives, and a sensor that is directly related to the displacement of the driven object of the motor with the encoder is connected to an encoder different from the encoder itself (i.e., an encoder of a motor with another drive shaft), then the servo drive that needs the detection signal must obtain the required information from the other servo drives (i.e., the servo drives that receive the output of the aforementioned different encoders).

[0009] Thus, in order to properly obtain the detection signal from the corresponding sensor, the servo drive needs to establish an association between the servo drive and the sensor, that is, the servo drive needs to perform identification processing on the corresponding sensor. According to existing technology, even if the user reduces the wiring workload by wiring between the sensor and the encoder, if the subsequent association setup work between the servo drive and the sensor is quite demanding, its convenience will be lost.

[0010] The present invention was made in view of this problem, and its object is to provide a technique for realizing sensor recognition processing of servo drives in the case of a servo system containing multiple servo drives.

[0011] Methods for solving problems

[0012] One aspect of the present invention provides a servo driver configured to drive a first motor and also communicatively connect to other servo drivers. The servo driver is configured to receive detection signals from a first sensor that detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor, and to receive detection signals from other sensors configured to detect other parameters related to the displacement of the first driven object. Furthermore, the servo driver includes: a first processing unit that, when performing a first predetermined action that causes displacement of the first driven object by only driving the output shaft of the first motor while the sensor identification processing is incomplete, identifies the first sensor as a first corresponding sensor associated with the servo driver upon receiving a detection signal from the first sensor; and a second processing unit that, when performing the first predetermined action while the sensor identification processing is incomplete, identifies other sensors as other corresponding sensors according to predetermined information related to other sensors received from the other servo drivers, wherein the predetermined information related to other sensors enables the servo driver to identify the other sensors as other corresponding sensors associated with the servo driver.

[0013] The servo driver, together with the other servo drivers, constitutes a servo system. Furthermore, the two servo drivers are connected in a communicative manner, enabling the exchange of information required for separate servo control. Here, the first motor, driven and controlled by the servo driver, is configured to drive a first driven object, and parameters related to the displacement of this first driven object are detected by a sensor different from the first sensor. Moreover, the first sensor is configured to be received by the servo driver, while the other sensors are received by the other servo drivers. That is, the configuration is such that the detection signal from the first sensor is directly received by the servo driver that drives and controls the first motor, but the detection signals from the other sensors are not received by this servo driver, but by other servo drivers. Furthermore, examples of the first sensor and other sensors include origin sensors, limit sensors, and closed sensors paired with linear scales, which relate to the position of the first driven object.

[0014] Therefore, in order to utilize the detection signal from a sensor different from the first sensor, the servo driver requires sensor identification processing to enable other servo drivers that receive detection signals from other sensors to appropriately convey the presence of those other sensors to the servo driver. Thus, the servo driver implements sensor identification processing through the first processing unit and the second processing unit. During the processing of the two units, the servo driver executes a first predetermined action of the first motor. In this first predetermined action, only the first motor is driven; if other drive shafts exist in the servo system, other motors are not driven. Therefore, during the execution of the first predetermined action, the acquisition of certain detection signals by the sensor indicates that the sensor is related to the first motor, i.e., it is a sensor corresponding to the servo driver that drives and controls the first motor. Furthermore, the first predetermined action can be a movement action within the entire drivable range of the first driven object, from one end to the other, or it can be other types of actions.

[0015] Therefore, when the first processing unit receives a detection signal from the first sensor during the first prescribed operation, it identifies the first sensor as a sensor corresponding to the servo driver (corresponding sensor). Furthermore, when the second processing unit receives prescribed information related to other sensors from other servo drivers during the same first prescribed operation, it also identifies those other sensors as sensors corresponding to the servo driver (corresponding sensors). This prescribed information is a signal that enables the servo driver to identify other sensors as sensors corresponding to itself, and it is sent from other servo drivers. In this case, based on the ongoing first prescribed operation, while other servo drivers can identify that other sensors do not correspond to them, they cannot identify which servo driver they correspond to. Therefore, the prescribed information cannot contain information directly specifying the corresponding servo driver. However, since the prescribed information is sent in conjunction with the first prescribed operation, at least the servo driver that has performed the first prescribed operation can identify, upon receiving the prescribed information, that other sensors according to the prescribed information are sensors corresponding to that servo driver.

[0016] Thus, through the first processing unit and the second processing unit, the servo driver can appropriately identify, by means of the first predetermined action of the first motor, a first sensor configured to be directly received by the servo driver that drives and controls the first motor, and other sensors configured not to be received by the servo driver but by other servo drivers.

[0017] Here, the servo driver can also be configured to receive a detection signal from a second sensor, which detects parameters related to the displacement of a second driven object, which is driven by the second servo driver communicatively connected to the servo driver via the output shaft of a second motor. In this case, the servo driver may also include a transmitting unit that, when performing a second predetermined action of driving only the output shaft of the second motor to displace the second driven object while the sensor identification processing is incomplete, sends information related to the second sensor to the second servo driver upon receiving a detection signal from the second sensor. This information related to the second sensor enables the second servo driver to identify the second sensor as a second corresponding sensor associated with the second servo driver.

[0018] In the above scenario, a second sensor, not associated with the aforementioned servo driver, is configured to be received by the aforementioned servo driver. That is, the detection signal of the second sensor is not directly received by the second servo driver but is received by the aforementioned servo driver. Therefore, when the second predetermined operation, which only drives the second motor, is performed, the detection signal of the second sensor is input to the aforementioned servo driver instead of the second servo driver. The second predetermined operation is associated with the second motor and follows the first predetermined operation. Therefore, the aforementioned servo driver transmits information related to the second sensor to the second servo driver via a transmitting unit, thereby enabling the second servo driver, upon receiving this information, to identify the second sensor as a sensor corresponding to itself based on the information transmitted in association with the second predetermined operation. In this way, the servo driver can assist in the identification processing of corresponding sensors associated with servo drivers other than itself (the second servo driver) through the transmitting unit. Furthermore, the other servo drivers described above can also be the second servo driver.

[0019] Here, several methods are illustrated regarding the exchange of detection signals between the sensors and the servo driver. In a first method, the first motor may also include: a motor body containing the output shaft; and an encoder having a signal generation unit that detects the movement of the motor body driven by the servo driver and generates a feedback signal representing the detected movement. In this case, the first sensor may also be connected to the encoder via a sensor cable, and the servo driver may also obtain the feedback signal generated by the signal generation unit and the detection signal of the first sensor transmitted via the sensor cable via a communication cable connected to the encoder. Thus, by wiring the encoder and the first sensor using a sensor cable, and transmitting the feedback signal and the detection signal of the first sensor to the servo driver via the communication cable, the workload of sensor wiring can be reduced. Furthermore, the second sensor may also be connected to the encoder via a sensor cable, and similarly, the detection signal of the second sensor and the feedback signal are transmitted together to the servo driver via the communication cable.

[0020] Furthermore, in the above-described configuration, the first sensor can also be powered by the encoder via the sensor cable. This structure eliminates the need for a power supply to the sensor itself. Alternatively, the encoder can have a display unit that indicates the presence of a detection signal when it is received from the first sensor via the sensor cable. With this structure, the user can visually confirm the input of the detection signal from the first sensor based on the content displayed on the display unit.

[0021] Next, as a second method, the first sensor can also be communicatively connected to the servo driver wirelessly, or via a predetermined device capable of communicating with the first sensor wirelessly. In this case, the servo driver can also acquire the detection signal of the first sensor wirelessly, or via the predetermined device. By utilizing wireless, the wiring workload of the sensor can be reduced. Furthermore, the second sensor can also transmit its detection signal to the servo driver wirelessly.

[0022] The servo driver described above may also include a determination unit that determines the sensor type of the first sensor identified by the first processing unit and the other sensors identified by the second processing unit based on the position information within the driving range of the first driven object when each sensor is identified. By determining the sensor type during the corresponding sensor identification process, user convenience can be further improved.

[0023] Alternatively, the servo driver of this application can be understood from other aspects. For example, the servo driver is configured to drive a first motor. Moreover, the first motor may have: a motor body including an output shaft; and an encoder having a signal generation unit that detects the movement of the motor body driven by the servo driver and generates a feedback signal representing the detected movement. A first sensor that detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor is connected to the encoder via a sensor cable, thereby sending the detection signal of the first sensor to the encoder, and the first sensor is powered by the encoder via the sensor cable. The servo driver obtains the feedback signal generated by the signal generation unit via a communication cable connected to the encoder, and obtains the detection signal of the first sensor transmitted via the sensor cable.

[0024] The invention can also be understood from the perspective of a servo system. Specifically, the servo system includes: a first servo driver configured to drive a first motor; and a second servo driver communicatively connected to the first servo driver and configured to drive a second motor. The first servo driver is configured to receive a detection signal from a first sensor that detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor. The second servo driver is configured to receive detection signals from other sensors that detect other parameters related to the displacement of the first driven object. Furthermore, the second servo driver is configured such that, when a first predetermined action is performed—causing displacement of the first driven object by only driving the output shaft of the first motor—before the sensor identification processing is completed, the second servo driver, upon receiving a detection signal from the other sensor, sends information related to that other sensor to the first servo driver. This information enables the first servo driver to identify the other sensor as another corresponding sensor associated with it. The first servo driver is configured to identify the other sensor as the other corresponding sensor based on the information related to it. According to this structure, by means of the first predetermined action of the first motor, the first servo driver can appropriately identify other sensors configured to be received by the second servo driver but not by the first servo driver that drives the first motor.

[0025] Alternatively, in the aforementioned servo system, the first servo driver may also be configured such that, when the first predetermined action is performed before the sensor identification processing is complete, and the first servo driver receives a detection signal from the first sensor, it identifies the first sensor as the first corresponding sensor associated with the first servo driver. According to this configuration, by means of the first predetermined action of the first motor, the first servo driver can appropriately identify the first sensor configured to be directly received by the servo driver that drives and controls the first motor.

[0026] Furthermore, the technical concepts disclosed in the servo drivers up to the above can be applied to the aforementioned servo systems as long as there are no technical inconsistencies.

[0027] The present invention can also be understood from the perspective of a sensor identification and processing method. Specifically, the sensor identification and processing method is a servo system-based sensor identification and processing method, the servo system comprising: a first servo driver configured to drive a first motor; and a second servo driver communicatively connected to the first servo driver, configured to drive a second motor. The first servo driver is configured to receive a detection signal from a first sensor that detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor, and the second servo driver is configured to receive detection signals from other sensors that detect other parameters related to the displacement of the first driven object. Furthermore, the method includes the following steps: when a first predetermined action is performed, causing displacement of the first driven object by only driving the output shaft of the first motor, while the sensor identification processing is not yet complete, and the second servo driver receives a detection signal from the other sensor, the second servo driver sends information related to the other sensor to the first servo driver, the information related to the other sensor being used to enable the first servo driver to identify the other sensor as another corresponding sensor associated with the first servo driver; and the first servo driver identifies the other sensor as the other corresponding sensor according to the information related to the other sensor. According to this structure, by means of the first predetermined action of the first motor, the first servo driver can appropriately identify other sensors configured to be received by the second servo driver but not by the first servo driver that drives the first motor.

[0028] Alternatively, the sensor identification processing method described above may also include the following step: when the first predetermined action is performed before the sensor identification processing is completed, and the first servo driver receives a detection signal from the first sensor, the first servo driver identifies the first sensor as the first corresponding sensor associated with the first servo driver. According to this structure, by means of the first predetermined action of the first motor, the first servo driver can appropriately identify the first sensor configured to be directly received by the servo driver that drives and controls the first motor.

[0029] Furthermore, the technical concepts disclosed in the servo drivers up to the above can be applied to the sensor identification and processing method, provided that no technical inconsistencies arise.

[0030] Invention Effects

[0031] In the case of a servo system containing multiple servo drives, it is possible to realize sensor recognition processing of the servo drives. Attached Figure Description

[0032] Figure 1 Figure 1 shows a schematic structure of a servo system according to an embodiment of the present invention.

[0033] Figure 2 This is Figure 1, which shows the general structure of a motor.

[0034] Figure 3 This is a diagram showing the functional structure of a servo driver.

[0035] Figure 4 It is a flowchart showing the process executed in each driver during sensor identification processing.

[0036] Figure 5 It indicates that it has been carried out. Figure 4 The flowchart shown illustrates the specific processing flow between the PLC and servo drive during sensor identification and processing.

[0037] Figure 6 Figure 2 shows a schematic structure of a servo system according to an embodiment of the present invention.

[0038] Figure 7 Figure 3 shows a schematic structure of a servo system according to an embodiment of the present invention.

[0039] Figure 8 Figure 4 shows a schematic structure of a servo system according to an embodiment of the present invention. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in the drawings are labeled with the same reference numerals, and their descriptions will not be repeated. In this disclosure, an industrial system is shown as an example of a servo system. However, the application of the servo system of the present invention is not particularly limited.

[0041] <First Implementation>

[0042] Figure 1 This is a block diagram that roughly represents the structure of a servo system 100. (Refer to...) Figure 1The servo system 100 includes a PLC (Programmable Logic Controller) 1, and servo drivers 2 and 2a. Servo drivers 2 and 2a are configured to drive and control servo motors 3 and 3a respectively. The output shafts 32 and 32a of each of the servo motors 3 and 3a are connected to lead screw shafts 52 and 52a via couplings 51 and 51a. Precision worktables 53 and 53a are respectively disposed at the lead screw shafts 52 and 52a, configured to be displaced by the servo motors 3 and 3a. Workpieces 8 and 8a are respectively placed on the precision worktables 53 and 53a. Thus, the servo system 100 shown in the figure has two drive axes: one based on motor 3 and the other based on motor 3a, but more than three drive axes can also be provided.

[0043] Furthermore, a linear scale 54, an origin sensor 61, limit sensors 62 and 63, and a fully-closed sensor 64 are arranged at the drive shaft of motor 3, and a linear scale 54a, an origin sensor 61a, limit sensors 62a and 63a, and a fully-closed sensor 64a are arranged at the drive shaft of motor 3a. These sensors detect parameters related to the displacement of the precision worktables 53 and 53a, which are their respective objects of detection.

[0044] Origin sensors 61 and 61a detect the origin position of precision worktables 53 and 53a, outputting an ON signal when each worktable reaches its respective origin position and an OFF signal when it is in a different position. Limit sensors 62, 63, 62a, and 63a detect the end positions of the movable range of precision worktables 53 and 53a on each drive shaft, outputting an ON signal when each worktable reaches its respective end position and an OFF signal when it is in a different position. For example, the configuration is such that when limit sensors 62, etc., are ON, the precision worktable 53 is stopped by stopping the motor 3. Such origin and limit sensors can be photoelectric sensors, proximity sensors, fiber optic sensors, etc. Alternatively, image sensors can also be used as origin and limit sensors. In this case, the detection signals of each sensor are image signals.

[0045] Furthermore, linear scales 54 and 54a are arranged along the axial direction of lead screw shafts 52 and 52a. The linear scales 54 and 54a are, for example, reflective photoelectric glass scales with equally spaced slits. Moreover, fully enclosed sensors 64 and 64a are mounted on precision worktables 53 and 53a and move integrally with them. The fully enclosed sensors 64 and 64a have a light-emitting portion and a light-receiving portion (neither shown). Light emitted from the light-emitting portion is reflected by the slits of the corresponding linear scales 54 and 54a, generating interference fringes on the light-receiving portion. When the precision worktables 53 and 53a move, the interference fringes also move, therefore the intensity of the output signal from the light-receiving portion changes according to the movement of the precision worktables 53 and 53a. Therefore, by monitoring the intensity change of the output signal from the light-receiving portion, the amount of movement of the precision worktables 53 and 53a can be determined. That is, the fully enclosed sensors 64 and 64a output detection signals for calculating the movement of the precision worktables 53 and 53a, and these detection signals are used for the fully enclosed control in the servo drives 2 and 2a.

[0046] Here, PLC 1 outputs command signals to servo drives 2 and 2a. PLC 1 functions as a monitoring device for servo drives 2 and 2a by executing processes according to a pre-prepared program.

[0047] Furthermore, servo drives 2 and 2a receive command signals from PLC 1. They also receive feedback signals from motors 3 and 3a, respectively, and receive detection signals output from corresponding origin sensors 61 and 61a, limit sensors 62, 63, 62a, 63a, or fully enclosed sensors 64 and 64a. Each servo drive 2 and 2a contains a servo system that utilizes feedback control via position controllers, speed controllers, current controllers, etc., to perform servo control and drive motors 3 and 3a using these signals.

[0048] Additionally, motor 3 includes a motor body 30 and an encoder 31, and motor 3a includes a motor body 30a and an encoder 31a. Motors 3 and 3a are, for example, AC servo motors. Motors 3 and 3a are supplied with drive current from servo drivers 2 and 2a via power lines 40 and 40a, respectively. Encoders 31 and 31a detect the movement of motor bodies 30 and 30a, respectively. Encoders 31 and 31a output feedback signals representing the detected movement to servo drivers 2 and 2a via encoder cables 41 and 41a, respectively.

[0049] Next, the wiring of each sensor will be explained. As described above, the origin sensor 61, limit sensors 62 and 63, and the fully enclosed sensor 64 are assigned to the drive shaft associated with the motor 3, while the origin sensor 61a, limit sensors 62a and 63a, and the fully enclosed sensor 64a are assigned to the drive shaft associated with the motor 3a. However, in Figure 1 In the illustrated configuration, the sensor cables from each sensor may not necessarily be connected to the encoder of the motor assigned to that drive shaft, but rather to the encoder of the motor closer to that sensor. For example, for the origin sensor 61 and limit sensor 63 assigned to motor 3, encoder 31a is configured closer than encoder 31. Therefore, in this embodiment, cable 71 from origin sensor 61 and cable 73 from limit sensor 63 are connected to encoder 31a. This structure is achieved by configuring multiple encoders.

[0050] Similarly, the origin sensor 61a and the limit sensor 63a are assigned to the motor 3a, but the encoder 31 is positioned closer to the origin sensor 61a and the limit sensor 63a than the encoder 31a. Therefore, in this embodiment, the cable 71a from the origin sensor 61a and the cable 73a from the limit sensor 63a are connected to the encoder 31.

[0051] Furthermore, the remaining sensors (limit sensor 62, fully enclosed sensor 64, limit sensor 62a, and fully enclosed sensor 64a) can also be connected via cables to the encoders located closer to the encoders in encoders 31 and 31a. However, in Figure 1 In the structure shown, limit sensor 62 and fully enclosed sensor 64 are connected to encoder 31 via cables 72 and 74, respectively, and limit sensor 62a and fully enclosed sensor 64a are connected to encoder 31a via cables 72a and 74a, respectively. That is, regarding these sensors, the encoder located closer to the sensor is the same as the encoder that detects the movement of the motor to which the sensor is assigned.

[0052] Next, based on Figure 2 The functional structure of the encoders 31 and 31a, which connect the sensors via cables as described above, will be explained. Furthermore, Figure 2 The structure of encoder 31 is shown in a representative and simplified manner, but encoder 31a has the same functional structure in substance. Encoder 31 includes a signal generation unit 311, an input unit 312, an A / D (analog-to-digital) conversion unit 313, a communication unit 314, a power supply unit 315, and a display unit 316.

[0053] The signal generation unit 311 detects the movement of the motor body 30 of the motor 3 driven by the servo driver 2 and generates a feedback signal representing the detected movement. The feedback signal is output to the communication unit 314. The feedback signal may include, for example, information about the rotational position (angle) of the rotation axis of the motor body 30, information about the rotational speed of the rotation axis, and information about the rotational direction of the rotation axis. The structure of the signal generation unit 311 may, for example, employ a known incremental or absolute structure.

[0054] The input unit 312 receives detection signals from each sensor. In the encoder 31 of this embodiment, the cables 72 of the limit sensor 62, 74 of the fully enclosed sensor 64, 71a of the origin sensor 61a, and 73a of the limit sensor 63a are connected to the input unit 312. The input unit 312 is, for example, a terminal block or connector for connecting wiring. The input unit 312 functions as an input interface for receiving detection signals from each sensor via each cable. The input detection signals are output from the input unit 312 to the A / D conversion unit 313. The A / D conversion unit 313 performs A / D conversion on the detection signals from the input unit 312 and outputs the converted digital signal to the communication unit 314.

[0055] The communication unit 314 is an interface for communicating with the servo driver 2. In this embodiment, the communication unit 314 transmits feedback signals and detection signals from each sensor to the servo driver 2 via the encoder cable 41. Additionally, in the encoder 3a, feedback signals and detection signals from each sensor are transmitted to the servo driver 2a via the encoder cable 41a. In this embodiment, serial communication is used in the transmission of feedback signals and detection signals from the communication unit 314. This reduces the number of signal lines in the cable. For serial communication based on the encoder cable 41, known communication standards such as RS-232C (Recommended Standards 232), RS-422, or RS-485 can be used. Furthermore, power is supplied to the encoder 31 from the servo driver 2 via the encoder cable 41.

[0056] The power supply unit 315 supplies a portion of the power obtained from the servo driver 2 via the encoder cable 41 to the functional units of each sensor connected by cable. A portion of this power is transferred from the communication unit 314 to the power supply unit 315. Furthermore, in Figure 2 The diagram describes the cables connected to the input unit 312 and the cables connected to the power supply unit 315, but in reality, the transmission and reception of detection signals from each sensor and the supply of power are performed via the same cable. Alternatively, the cables connecting each sensor to the input unit 312 and the cables connecting to the power supply unit 315 may be wired separately.

[0057] The display unit 316 is an LED that illuminates according to the detection signal input from each sensor to the input unit 312. That is, LEDs are arranged in the encoder 31 according to the number of cables of each connected sensor, and when a detection signal is input, the LED corresponding to the sensor that sent the detection signal is illuminated. Alternatively, the display unit 316 may not be an LED but a display such as an LCD, in which case the sensor with the detection signal input can also be displayed on the display.

[0058] Furthermore, in the servo system 100, when the servo drives 2 and 2a are capable of performing servo control of their corresponding motors 3 and 3a, each encoder 31 and 31a has an operating mode corresponding to its use when the servo drives 2 and 2a can communicate with each other. In this operating mode, each encoder 31 and 31a sends detection signals from each sensor to the servo drive, and these detection signals need to reach the specific servo drive that requires them. The servo drives 2 and 2a are connected via a communication cable 42. Each servo drive 2 and 2a transmits the detection signals from its respective sensor to the servo drive that requires them, or receives them itself.

[0059] For example, servo driver 2 receives detection signals from encoder 31 from limit sensor 62, fully enclosed sensor 64, origin sensor 61a, and limit sensor 63a. The detection signals from limit sensor 62 and fully enclosed sensor 64 are signals that should be processed by servo driver 2, while the detection signals from origin sensor 61a and limit sensor 63a are signals that should be processed by servo driver 2a. Therefore, servo driver 2 transmits the detection signals from origin sensor 61a and limit sensor 63a to servo driver 2a.

[0060] Similarly, servo driver 2a receives detection signals from encoder 31a from origin sensor 61, limit sensor 63, limit sensor 62a, and enclosed sensor 64a. The detection signals from limit sensor 62a and enclosed sensor 64a are signals that should be processed by servo driver 2a, while the detection signals from origin sensor 61 and limit sensor 63 are signals that should be processed by servo driver 2. Therefore, servo driver 2a transmits the detection signals from origin sensor 61 and limit sensor 63 to servo driver 2.

[0061] Therefore, in order to distribute detection signals among servo drives, it is necessary to associate the sensor that sends the detection signal with the servo drive corresponding to the destination of the detection signal, that is, the servo drive's identification processing for the corresponding sensor (the sensor corresponding to the servo drive). The following is an explanation of this identification processing.

[0062] Here, Figure 3 This shows a schematic structure of the functional units of servo drive 2. Servo drive 2 can be considered as a computer with a computing unit, storage unit, etc. Figure 3 The functional units shown are implemented by executing a prescribed program in the servo driver 2. Furthermore, the servo driver 2a also has the same functional units, therefore a detailed description of the servo driver 2a is omitted. The servo driver 2 has a communication unit 21, a servo control unit 22, a storage unit 23, a first processing unit 24, a second processing unit 25, a decision unit 26, and a transmission unit 27, but may also have functional units other than these.

[0063] The communication unit 21 is a functional unit responsible for communicating with external devices via the communication cable 42. For example, the communication unit 21 functions as an interface for communication with the PLC 1 and other servo drives (servo drive 2a, etc.). Furthermore, the communication unit 21 also functions as an interface for communication with the encoder 31 via the encoder cable 41. The servo control unit 22 is a functional unit for servo controlling the motor 3 based on instructions from the PLC 1. Specifically, it performs feedback control using a position controller, speed controller, current controller, etc., and utilizes detection signals from various sensors assigned to the servo drive 2 in this feedback control. Additionally, it appropriately sets control parameters such as speed gain for the position controller, speed controller, current controller, etc., to appropriately perform servo control of the motor 3, which is the controlled object. The storage unit 23 is a functional unit that stores information related to the processing performed by the servo drive 2, such as information required for the servo control of the motor 3 and information required for the servo drive to process the corresponding sensors. Furthermore, information indicating the association between the servo drive and each sensor (correspondence information), determined by the identification processing of the corresponding sensors described later, is stored in the storage unit 23. Based on this stored correspondence information, the servo drive 2 assigns the destination of the detection signals sent from each sensor and, as needed, processes the transmission of detection signals from specific sensors to the destination servo drive via the communication unit 21.

[0064] The first processing unit 24 is a functional unit that, when receiving a detection signal from a specific sensor during the first predetermined action of displacing the precision worktable 53 by driving the output shaft 32 of the drive motor 3, identifies that specific sensor as a corresponding sensor associated with the servo drive 2. This specific sensor is one that has not yet been identified by the servo drive 2 but is configured so that its detection signal is received by the servo drive 2 and should ultimately be assigned to the servo drive 2; in this embodiment, it corresponds to the limit sensor 62 and the fully enclosed sensor 64. Furthermore, the first predetermined action is a movement of the precision worktable 53 within its entire drivable range from one end to the other.

[0065] The second processing unit 25 is a functional unit that, when the first predetermined operation is performed, receives information from a servo driver other than the servo driver 2 (servo driver 2a in this embodiment) regarding a sensor different from the specific sensor described above, identifies the sensor different from the specific sensor as a corresponding sensor associated with the servo driver 2 based on the received information. This sensor different from the specific sensor is one that has not yet been identified by the servo driver 2 but is configured to have its detection signal received by the servo driver 2a and should ultimately be assigned to the servo driver 2; in this embodiment, it corresponds to the origin sensor 61 and the limit sensor 63. Furthermore, the information related to the origin sensor 61 and the limit sensor 63 is transmitted from the servo driver 2a to the servo driver 2 via the transmission unit 27 (described later) provided by the servo driver 2a.

[0066] The determination unit 26 is a functional unit that determines the sensor type of the sensors identified by the first processing unit 24 and the sensors identified by the second processing unit 25 based on the position information of the precision worktable 53 when each sensor is identified. The detection signals of each origin sensor 61, limit sensors 62, 63, and fully enclosed sensor 64 change with the displacement of the precision worktable 53, therefore, the detection signals are strongly correlated with the position of the precision worktable 53. Using this correlation, the determination unit 26 performs sensor type determination processing.

[0067] The transmitting unit 27 is a functional unit that, when receiving a detection signal from a specific sensor during a second predetermined operation that causes displacement of the precision worktable 53a by driving only the output shaft of a motor 3a corresponding to a servo drive different from servo drive 2 (servo drive 2a in this embodiment), transmits information related to that specific sensor to the servo drive 2a. This information is used to enable the servo drive 2a to identify the specific sensor as a sensor associated with it. The specific sensor is a sensor that has not yet been identified by the servo drive 2a but is configured such that its detection signal is received by the servo drive 2a and should ultimately be assigned to the servo drive 2a. In this embodiment, this corresponds to the origin sensor 61a and the limit sensor 63a. Furthermore, the second predetermined operation is a movement of the precision worktable 53a within its entire drivable range from one end to the other.

[0068] Next, based on Figure 4 as well as Figure 5 The sensor identification processing achieved through the collaboration of these functional units will be explained. Figure 4 This is a flowchart that roughly represents the processing flow performed by servo drives 2 and 2a respectively. Figure 5 This is a flowchart that roughly represents the processing flow between PLC 1, servo drivers 2 and 2a when performing sensor identification processing.

[0069] First, based on Figure 4 The processing flow performed by each servo driver will be explained. Furthermore, the following explanation will focus on servo driver 2. Figure 4The process shown is repeated at predetermined time intervals. First, in S101, it is determined whether an instruction to perform sensor identification processing has been received from PLC 1. If an affirmative determination is made in S101, the process proceeds to S102; if a negative determination is made, the process temporarily ends. In S102, the sequence of scanning actions in each servo drive is obtained according to the sensor identification processing instruction received from PLC 1. This scanning action refers to the first predetermined action and the second predetermined action performed for the processing of the first processing unit 24 and the second processing unit 25 described above. That is, the scanning action is the operation of the motor as follows: in order to extract the sensor that emits a detection signal in a manner corresponding to the driving action when only the corresponding motor is driven in each drive shaft performing sensor identification processing, the precision worktable is moved from one end of the drive shaft to the other, that is, the entire range of motion. More specifically, the motor 3 is driven at a low and constant speed from the point where the precision worktable 53 contacts a stop (not shown) located at one end of the movable range along the lead screw shaft 52 until the precision worktable 53 contacts a stop (not shown) located at the other end. Furthermore, during this drive, torque control of the motor 3 is performed to minimize the impact when the precision worktable 53 contacts the stop. In this embodiment, the scanning sequence of the drive axes of the servo drives 2 and 2a is set to 1 and 2, respectively.

[0070] In S103, it is determined whether the scanning sequence of the servo drive 2 has arrived. If a positive determination is made in S103, the process proceeds to S104; if a negative determination is made, the process proceeds to S106. In S104, the scanning operation of the servo drive 2 using the drive shaft, i.e., the scanning operation using the motor 3, begins. At this time, if a limit sensor 62 is configured at one end of the lead screw 52 and a limit sensor 63 is configured at the other end, the scanning operation sends detection signals from each sensor to the servo drive 2 and 2a via encoders 31 and 31a connected to the destination, in the order of limit sensor 62, origin sensor 61, and limit sensor 63. Furthermore, the detection signal from the fully enclosed sensor 64 is continuously sent to the servo drive 2 during the scanning operation. In addition, a display unit 316 is provided on the encoders 31 and 31a. When the detection signals from each sensor are input to each encoder, the diodes on the display unit 316 light up at the input timing of the detection signals. Thus, the user can visually confirm the input of the sensor detection signals. Furthermore, the detection signals from each sensor include identification information for recognizing the sensor that generated the signal, allowing each servo driver receiving the detection signal to determine which sensor the signal originated from. After processing in S104 is complete, the process proceeds to S105.

[0071] In S105, sensor identification processing based on the first processing unit 24 and the second processing unit 25 is performed according to the scanning operation that started in S104. Specifically, along with the scanning operation, the detection signals of the limit sensor 62 and the fully enclosed sensor 64 arrive at the servo driver 2, whereby the first processing unit 24 identifies these sensors as sensors corresponding to the servo driver 2. Furthermore, along with the scanning operation, the detection signals of the origin sensor 61 and the limit sensor 62 arrive at the servo driver 2a, whereby the transmitting unit (equivalent to...) of the servo driver 2a... Figure 3 The functional unit of the transmitting unit 27 sends information related to these sensors to the servo driver 2, which is a servo driver other than itself, and receives it via the communication unit 21. This sensor-related information includes identification information for each sensor. As a result, based on the received information, the second processing unit 25 identifies these sensors as also corresponding to the servo driver 2.

[0072] Furthermore, in S105, the determination unit 26 determines the type of sensor. Specifically, among the limit sensors 62 and 63, the origin sensor 61, and the fully enclosed sensor 64, limit sensors 62 and 63 emit detection signals when the position of the precision worktable 53 is at the outermost edge of its movable range. Therefore, the sensor type can be determined as "limit sensor" based on the position information of the precision worktable 53 when it emits the detection signal (meaning the position information at the outermost edge). In addition, the type of sensor that emits a detection signal in the middle of the movable range of the precision worktable 53 can be determined as "origin sensor". Furthermore, the type of sensor that emits a detection signal continuously during the scanning operation, that is, regardless of the position of the precision worktable 53, can be determined as "fully enclosed sensor". After the processing of S105 is completed, the process proceeds to S109.

[0073] Furthermore, in S106, after making a negative determination in S103, the system waits for the scanning operation at other drive axes to be executed. In this embodiment, when the servo drive 2a performs a scanning operation using a drive axis, the servo drive 2 enters a standby state after processing in S106. However, at this time, the servo drive 2 also receives detection signals from the origin sensor 61a and the limit sensor 63a assigned to the servo drive 2a. Therefore, in S107, it is determined whether a detection signal has been received from any sensor. This sensor is a sensor that should be associated with a servo drive different from the servo drive 2. Therefore, if a positive determination is made in S107, the process proceeds to S108, and sensor information related to this sensor is sent through the transmission unit 27. Furthermore, the destination of this sensor information is the servo drive corresponding to the drive axis that is performing a scanning operation when the detection signal is received. The servo drive at the destination can query the PLC 1 and the target servo drive 2 via the communication cable 42. When the processing in S108 is completed, the process proceeds to S109. If a negative determination is made in S107, the process proceeds to S109.

[0074] In S109, it is determined whether the scanning operation at all drive axes in the servo system 100 has been completed. If a positive determination is made in S109, the process ends; if a negative determination is made, the process from S103 onwards is repeated. Furthermore, in the case of a positive determination in S109, as sensors corresponding to the servo driver 2, the origin sensor 61, limit sensors 62 and 63, and fully enclosed sensor 64 are identified, and the association information between the servo driver 2 and each sensor is stored in the storage unit 23.

[0075] Next, based on Figure 5 Executed by servo drivers 2 and 2a respectively Figure 4 The handover between PLC 1, servo drives 2 and 2a during the processing is explained. First, in S11, PLC 1 issues an instruction for sensor identification processing to all servo drives 2 and 2a included in the servo system 100. Following this instruction, each servo drive executes the process. Figure 4 The processing shown. Furthermore, through... Figure 4 The processing in S102 and S103 first involves driving motor 3 in servo driver 2 in S21 to start the scanning action (see...). Figure 4 (The process in S104). At this time, motor 3a stops (refer to the process in S31). Then, along with this scanning action, in S22, the detection signals of limit sensor 62 and fully enclosed sensor 64 are received by servo driver 2 via encoder 31.

[0076] Furthermore, accompanying the scanning action, the detection signals from the origin sensor 61 and the limit sensor 63 are received by the servo driver 2a via the encoder 31a (refer to the processing in S32). At this time, the servo driver 2a is in a state of... Figure 4 The process shown in S106 waits for the servo driver 2 to perform a scanning motion using the drive shaft. Upon receiving these detection signals, the servo driver 2a sends information related to the sensor that generated these detection signals to the servo driver 2 via its own transmitter 27 (refer to the process in S33). Then, in S23, the servo driver 2 receives this sensor-related information.

[0077] Then, in S24, the origin sensor 61, limit sensors 62 and 63, and fully enclosed sensor 64 are identified as sensors corresponding to the servo driver 2, and in S25, the sensor type of each sensor is determined (see reference). Figure 4 (Processing in S105). The sensor identification result and the sensor type determination result are stored in the storage unit 23 of the servo driver 2. After the sensor type determination is completed, in S26, the servo driver 2 notifies the servo driver 2a of the drive shaft that the scanning operation using the drive shaft has ended. Thus, the servo driver 2a knows that the sequence of scanning operations at its own drive shaft has arrived. In addition, after the notification, the motor 3 stops with respect to the servo driver 2 (refer to the processing in S27), and the servo driver 2... Figure 4 The process shown in S106 results in a state where the servo driver 2a is waiting for the scanning action of the drive shaft.

[0078] Next, in S34, the scanning action begins by driving motor 3a in servo driver 2a (see reference). Figure 4 (Processing in S104). Then, along with the scanning action, in S35, the detection signals of the limit sensor 62a and the fully enclosed sensor 64a are received by the servo driver 2a via the encoder 31a.

[0079] Furthermore, accompanying the scanning operation, the detection signals from the origin sensor 61a and the limit sensor 63a are received by the servo driver 2 via the encoder 31 (see process S28). The servo driver 2, having received these detection signals, transmits information related to the sensors that generated these detection signals to the servo driver 2a via its own transmitting unit 27 (see process S29). Then, in S36, the servo driver 2a receives this sensor-related information.

[0080] Subsequently, in S37, the origin sensor 61a, limit sensors 62a, 63a, and fully enclosed sensor 64a are identified as sensors corresponding to the servo driver 2a, and in S38, the sensor type of each sensor is determined (see reference). Figure 6 (Processing in S105). The sensor identification result and the sensor type determination result are stored in the storage unit 23 of the servo driver 2a. After the sensor type determination is completed, in S39, based on the fact that the servo driver 2a has completed the scanning operation of the drive axis, it notifies PLC 1 that the scanning operation at all drive axes has ended. Thus, PLC 1 knows in S12 that the sensor identification process has been completed.

[0081] By performing the sensor identification processing in the servo system 100 described above, servo drives 2 and 2a can identify their respective corresponding sensors, resulting in the appropriate arrival of the detection signals from each sensor at the assigned servo drive. In this sensor identification processing, it is not necessary to connect each sensor to the encoder of the motor driven by its corresponding servo drive; even when connected to the encoder of a nearby motor, appropriate association processing between the servo drive and each sensor can be achieved. Therefore, while reducing the workload of sensor wiring, it is easy to construct a servo system 100 for servo control of each drive axis.

[0082] <Second Implementation Method>

[0083] based on Figure 6 The second embodiment of this disclosure will be described. Figure 6 This is a block diagram that schematically illustrates a structural example of the servo system 100 of this embodiment. The encoder 31a also has the same structure as the encoder 31.

[0084] In this embodiment, some of the sensors disposed on each drive shaft have wireless communication capabilities. In the first embodiment, the detection signals from each sensor are input to the encoders 31, 31a of motors 3, 3a, and then reach the servo drives 2, 2a via encoder cables 41, 41a. However, in this embodiment, the detection signals from each sensor reach the corresponding servo drive via wireless communication. In this case, in order for the servo control unit 22 to perform servo control of motors 3, 3a using the detection signals from each sensor, the detection signals from each sensor also need to reach the assigned servo drives 2, 2a appropriately. Therefore, the servo drives 2, 2a are required to properly identify the corresponding sensors.

[0085] Here, based on Figure 7The structure of the servo system 100 in this embodiment will be described. Regarding the drive shaft of the precision worktable 53 driven by the motor 3, i.e., the drive shaft of the servo driver 2, the origin sensor 61, limit sensors 62, and 63 have wireless communication capabilities. On the other hand, the fully enclosed sensor 64 is connected to the encoder 31 via cable 74, similar to the first embodiment. Therefore, only the detection signal from the fully enclosed sensor 64 is input to the input section 312 of the encoder 31, and power is supplied to the fully enclosed sensor 64 from the power supply section 315. Furthermore, the communication section 21 of the servo driver 2 has a communication function for wireless communication with the origin sensor 61, limit sensors 62, and 63. In addition, each sensor with wireless communication capabilities has an internal battery and does not receive power from an external source. Alternatively, each sensor may be configured to receive power from an external source (e.g., the encoder 31) via a power line (not shown).

[0086] Furthermore, regarding the drive shaft of the precision worktable 53a driven by motor 3a, i.e., the drive shaft utilizing servo driver 2a, the origin sensor 61a, limit sensors 62a, and 63a have wireless communication capabilities. On the other hand, the fully enclosed sensor 64a is connected to the encoder 31a via cable 74a, similar to the first embodiment. Therefore, only the detection signal from the fully enclosed sensor 64a is input to the input section 312 of the encoder 31a, and power is supplied to the fully enclosed sensor 64a from the power supply section 315. In addition, the communication section of servo driver 2a has a communication function for wireless communication with the origin sensor 61a, limit sensors 62a, and 63a.

[0087] Here, we envision a state where the wireless sensors are not being identified by the servo drivers 2 and 2a. In this state, the detection signals from the wireless sensors can be received wirelessly by each of the servo drivers 2 and 2a, but each servo driver is unaware of which sensor's detection signal was assigned to it, making servo control of the motor by each servo driver impossible. Therefore, by applying the sensor identification processing disclosed in the first embodiment to the servo system 100 in this state where the sensor identification processing of the servo drivers is incomplete, the association between the servo drivers and each sensor can be appropriately achieved. Furthermore, in this embodiment, even before the sensor identification processing is completed, the detection signals from the wireless sensors are received by any servo driver, so each servo driver does not need to have a functional unit equivalent to the transmitting unit 27 shown in the first embodiment.

[0088] Furthermore, based on Figure 7 A variation of this embodiment will be described. Figure 6 Is with Figure 8Similarly, a block diagram of a structural example of the servo system 100 is shown in a simplified manner. In this modified example, the detection signals from each sensor are received once wirelessly by the repeater 150, and then reach each servo driver 2, 2a from the repeater 150. That is, the communication unit 21 of each servo driver 2, 2a does not have wireless functionality. However, in this case, in order to use the detection signals from each sensor to perform servo control of the motors 3, 3a by the servo control unit 22, the detection signals from each sensor must also reach the assigned servo drivers 2, 2a appropriately. Therefore, the servo drivers 2, 2a are required to properly identify the corresponding sensors. Therefore, similar to the second embodiment, by applying the sensor identification processing disclosed in the first embodiment, the association between the servo drivers and each sensor can be appropriately realized.

[0089] <Third Implementation Method>

[0090] based on Figure 8 The third embodiment of this disclosure will be described. Figure 4 This is a block diagram schematically illustrating a structural example of the servo system 100 of this embodiment. In the servo system 100 of this embodiment, only one drive shaft is included. Therefore, unlike the first embodiment, the origin sensor 61 and the limit sensor 63 are connected to the encoder 31 via cables 71 and 73, respectively. With this structure, the detection signals from the origin sensor 61 and the limit sensor 63 are sent to the encoder 31, and power is supplied from the encoder 31 to the origin sensor 61 and the limit sensor 63.

[0091] Such a system structure can also be practically applied. Figure 4 The sensor identification processing is shown. However, in this servo system 100, there is only one drive axis, so only one drive axis performs the scanning action, that is, only the motor 3 performs the scanning action. Moreover, the detection signals from the origin sensor 61, limit sensors 62, and 63 obtained based on this scanning action are temporarily all gathered at the servo driver 2 for the sensor identification processing described in S105. On the other hand, since there are no other drive axes, no other processing is performed. ​ The processing steps S106 to S108 are shown. As a result, sensor recognition processing can also be appropriately implemented in the servo system 100 with a single-axis drive shaft.

[0092] <Postscript 1>

[0093] A servo driver (2) configured to drive a first motor (3) and communicatively connected to other servo drivers (2a), receives detection signals from a first sensor (62, 64) configured to detect parameters related to the displacement of a first driven object (53) driven via the output shaft (32) of the first motor (3), and receives detection signals from other sensors (61, 63) configured to detect other parameters related to the displacement of the first driven object (53) from the other servo drivers (2a). The servo driver (2) includes a first processing unit 24 that, in a state where sensor identification processing is not completed, performs a process of moving the first driven object (53) by driving only the output shaft (32) of the first motor (3). When the first predetermined action is performed, if a detection signal is received from the first sensor (62, 64), the first sensor (62, 64) is identified as the first corresponding sensor associated with the servo driver (2); and when the second processing unit (25) performs the first predetermined action while the sensor identification processing is not completed, if it receives predetermined information related to other sensors (61, 63) from the other servo driver (2a), the other sensor (61, 63) is identified as another corresponding sensor according to the predetermined information, wherein the predetermined information related to other sensors (61, 63) is used to enable the servo driver (2) to identify the other sensor (61, 63) as the other corresponding sensor associated with the servo driver (2).

[0094] <Appendix 2>

[0095] A servo driver (2) configured to drive a first motor (3), the first motor (3) comprising: a motor body (30) including an output shaft (32); and an encoder (31) having a signal generation unit that detects the movement of the motor body (30) driven by the servo driver (2) and generates a feedback signal representing the detected movement; and a first sensor (62, 64) that detects parameters related to the displacement of a first driven object (53) driven via the output shaft (32) of the first motor (3) via a sensor line. The cables (72, 74) are connected to the encoder 31, thereby sending the detection signal of the first sensor (62, 64) to the encoder (31), and the first sensor (62, 64) is powered by the encoder (31) via the sensor cables (72, 74). The servo driver (2) obtains the feedback signal generated by the signal generation unit via the communication cable (41) connected to the encoder (31), and obtains the detection signal of the first sensor (62, 64) sent via the sensor cables (72, 74).

[0096] <Appendix 3>

[0097] A servo system (100) includes: a first servo driver (2) configured to drive a first motor (3); and a second servo driver (2a) communicatively connected to the first servo driver (2) and configured to drive a second motor (3a). The first servo driver (2) is configured to receive detection signals from first sensors (62, 64) that detect parameters related to the displacement of a first driven object (53) driven via the output shaft (32) of the first motor (3). The second servo driver (2a) is configured to receive detection signals from other sensors (61, 63) that detect other parameters related to the displacement of the first driven object (53). When the sensor identification process is not completed, and a first predetermined action is performed that only drives the output shaft (32) of the first motor (3) to displace the first driven object (32), if the second servo driver (2a) receives a detection signal from the other sensor (61, 63), it sends information related to the other sensor (61, 63) to the first servo driver (2) so that the first servo driver (2) can identify the other sensor (61, 63) as another corresponding sensor associated with the first servo driver (2). The first servo driver (2) is configured to identify the other sensor (61, 63) as the other corresponding sensor according to the information related to the other sensor (61, 63).

[0098] <Appendix 4>

[0099] A method for sensor identification processing of a servo system (100), the servo system (100) comprising: a first servo driver (2) configured to drive a first motor (3); and a second servo driver (2a) communicatively connected to the first servo driver (2) configured to drive a second motor (3a), the first servo driver (2) configured to receive detection signals from a first sensor (62, 64) that detects parameters related to the displacement of a first driven object (53) driven via the output shaft (32) of the first motor (3), and the second servo driver (2a) configured to receive detection signals from other sensors (61, 63) that detect other parameters related to the displacement of the first driven object (53), the method comprising the following steps Step: When the sensor identification process is not completed, and the first predetermined action is performed to drive the output shaft (32) of the first motor (3) to displace the first driven object (53), if the second servo driver (2a) receives a detection signal from the other sensor (61, 63), the second servo driver (2a) sends information related to the other sensor (61, 63) to the first servo driver (2) so that the first servo driver (2) can identify the other sensor (61, 63) as another corresponding sensor associated with the first servo driver (2); and the first servo driver (2) identifies the other sensor (61, 63) as the other corresponding sensor according to the information related to the other sensor (61, 63).

[0100] Label Explanation

[0101] 1: PLC; 2, 2a: Servo driver; 3, 3a: Motor; 24: First processing unit; 25: Second processing unit; 26: Decision unit; 27: Transmitting unit; 30, 30a: Motor body; 31, 31a: Encoder; 32, 32a: Output shaft; 53, 53a: Precision worktable; 54, 54a: Linear scale; 61, 61a: Origin sensor; 62, 62a, 63, 63a: Limit sensor; 64, 64a: Fully enclosed sensor; 100: Servo system; 150: Repeater; 311: Signal generation unit; 312: Input unit; 314: Communication unit; 315: Power supply unit; 316: Display unit.

Claims

1. A servo drive configured to drive a first motor and also communicatively connectable to other servo drives. The servo driver is configured to receive detection signals from a first sensor that detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor, and other servo drivers are configured to receive detection signals from other sensors that detect other parameters related to the displacement of the first driven object. The servo driver has: When the first processing unit performs a first predetermined action that displaces the first driven object by only driving the output shaft of the first motor while the sensor identification processing is incomplete, and receives a detection signal from the first sensor, it identifies the first sensor as the first corresponding sensor associated with the servo driver; and The second processing unit, when performing the first predetermined action while the sensor identification processing is incomplete, receives predetermined information related to other sensors from the other servo driver, and identifies the other sensor as another corresponding sensor according to the predetermined information, wherein... The specified information related to other sensors is used to enable the servo driver to identify the other sensors as the other corresponding sensors associated with the servo driver.

2. The servo driver according to claim 1, wherein, The servo driver is configured to receive a detection signal from a second sensor, which detects parameters related to the displacement of a second driven object, which is driven by the second servo driver communicatively connected to the servo driver via the output shaft of a second motor. The servo driver also includes a transmitting unit. When the transmitting unit performs a second predetermined action that drives only the output shaft of the second motor to cause displacement of the second driven object while the sensor recognition processing is not completed, it sends information related to the second sensor to the second servo driver when it receives a detection signal from the second sensor. The information related to the second sensor is used to enable the second servo driver to recognize the second sensor as a second corresponding sensor associated with the second servo driver.

3. The servo driver according to claim 2, wherein, The other servo driver is the second servo driver.

4. The servo driver according to claim 1, wherein, The first motor has: Motor body, which includes the output shaft; and An encoder having a signal generation unit that detects the movement of the motor body driven by the servo driver and generates a feedback signal representing the detected movement. The first sensor is connected to the encoder via a sensor cable. The servo driver obtains the feedback signal generated by the signal generation unit via a communication cable connected to the encoder, and obtains the detection signal of the first sensor transmitted via the sensor cable.

5. The servo driver according to claim 4, wherein, The first sensor is powered by the encoder via the sensor cable.

6. The servo driver according to claim 4, wherein, The encoder has a display unit that indicates the presence of a detection signal when a detection signal is input from the first sensor via the sensor cable.

7. The servo driver according to claim 1, wherein, The first sensor is communicatively connected to the servo driver via wireless means, or communicatively connected to the servo driver via a specified device capable of communicating with the first sensor wirelessly. The servo driver acquires the detection signal of the first sensor wirelessly or via the specified device.

8. The servo driver according to claim 1, wherein, The first defined action is a movement action of the first driven object within its entire drivable range, from one end to the other end.

9. The servo driver according to any one of claims 1 to 8, wherein, The servo driver further includes a determination unit that determines the sensor type of the first sensor identified by the first processing unit and the other sensors identified by the second processing unit based on the position information within the driving range of the first driven object when each sensor is identified.

10. A servo system comprising: a first servo driver configured to drive a first motor; and a second servo driver communicatively connected to the first servo driver and configured to drive a second motor. The first servo driver is configured to receive a detection signal from a first sensor, which detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor. The second servo driver is configured to receive detection signals from other sensors that detect other parameters related to the displacement of the first driven object. The second servo driver is configured such that, when performing a first predetermined action that displaces the first driven object by only driving the output shaft of the first motor, before the sensor identification processing is completed, the second servo driver, upon receiving a detection signal from the other sensor, sends information related to that other sensor to the first servo driver. This information enables the first servo driver to identify that other sensor as another corresponding sensor associated with the first servo driver. The first servo driver is configured to identify the other sensors as the other corresponding sensors based on information related to the other sensors.

11. The servo system according to claim 10, wherein, The first servo driver is further configured such that when the first predetermined action is performed while the sensor identification processing is incomplete, and the first servo driver receives a detection signal from the first sensor, it identifies the first sensor as the first corresponding sensor associated with the first servo driver.

12. The servo system according to claim 10, wherein, The first servo driver is also configured to receive a detection signal from a second sensor, which detects parameters related to the displacement of a second driven object driven via the output shaft of the second motor. The first servo driver is further configured such that, when a second predetermined action is performed that only drives the output shaft of the second motor to cause displacement of the second driven object while the sensor identification processing is not completed, the first servo driver, upon receiving a detection signal from the second sensor, sends information related to the second sensor to the second servo driver. The information related to the second sensor is used to enable the second servo driver to identify the second sensor as a second corresponding sensor associated with the second servo driver.

13. The servo system according to any one of claims 10 to 12, wherein, The first motor has: The motor body includes an output shaft; and An encoder having a signal generation unit that detects the movement of the motor body driven by the servo driver and generates a feedback signal representing the detected movement. The first sensor is connected to the encoder via a sensor cable. The servo driver obtains the feedback signal generated by the signal generation unit via a communication cable connected to the encoder, and obtains the detection signal of the first sensor transmitted via the sensor cable.

14. A method for sensor identification processing based on a servo system, the servo system comprising: a first servo driver configured to drive a first motor; and a second servo driver communicatively connected to the first servo driver, configured to drive a second motor. The first servo driver is configured to receive a detection signal from a first sensor, which detects parameters related to the displacement of a first driven object driven via the output shaft of the first motor. The second servo driver is configured to receive detection signals from other sensors that detect other parameters related to the displacement of the first driven object. The method includes the following steps: When, while sensor identification processing is incomplete, a first predetermined action is performed that only drives the output shaft of the first motor to displace the first driven object, and the second servo driver receives a detection signal from the other sensor, the second servo driver sends information related to the other sensor to the first servo driver. This information is used to enable the first servo driver to identify the other sensor as another corresponding sensor associated with the first servo driver. The first servo driver identifies the other sensors as the other corresponding sensors based on information related to the other sensors.

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