Control systems and multi-axis testing machines

Abstract

The multi-axis testing machine will immediately stop operating if an abnormality occurs. [Solution] In a control system in which a first control device 100 and a second control device 200 are connected via a synchronous communication line, the first control device 100 transmits a reply request signal containing reply request target identification information for identifying the second control device 200 that is the target of the reply request at a sampling period, and the second control device 200 transmits a reply signal if the target of the reply request identified by the reply request target identification information contained in the received reply request signal is the second control device 200.

Description

[Technical Field]

[0001] The present invention relates to a control system and a multi-axis testing machine. [Background Art]

[0002] Patent Document 1 discloses a multi-axis testing machine. In the multi-axis testing machine disclosed in Patent Document 1, a controller is provided for each actuator, and these controllers are monitored by an operation monitoring device. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 11-166878 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] When an abnormality occurs in a controller or an actuator controlled by the controller, it is necessary to stop the multi-axis testing machine. Generally, in a multi-axis testing machine in which a plurality of controllers are monitored by an operation monitoring device as shown in Patent Document 1, the operation monitoring device scans the plurality of controllers to check whether any abnormality has occurred, and if an occurrence of abnormality is detected, the operation monitoring device stops the controllers, that is, stops the operation of the multi-axis testing machine. Therefore, in such a multi-axis testing machine, a delay corresponding to the time required for scanning occurs from the occurrence of an abnormality to the stop of the operation of the multi-axis testing machine.

[0005] An object of the present invention is to immediately stop the operation of a multi-axis testing machine when an abnormality occurs. [Means for Solving the Problems]

[0006] To solve the above problems, a control system according to one embodiment of the present invention is a control system having a first control device and a second control device, wherein the first control device and the second control device are connected via a synchronous communication line, the first control device has a signal transmitting unit that transmits a reply request signal at a sampling period, the reply request signal includes reply request target identification information for identifying the second control device that is the target of the reply request, and the second control device has a signal receiving unit that receives the reply request signal, and a reply signal transmitting unit that transmits a reply signal if the target of the reply request identified by the reply request target identification information included in the reply request signal received by the signal receiving unit is the second control device.

[0007] The reply signal may include information indicating whether or not a stop request has occurred in the second control device that transmits the reply signal.

[0008] The reply request signal further includes reference signal information indicating whether or not the reply request signal is a reference signal for informing the second control device of the sampling period, and the signal transmission unit may transmit the reply request signal indicating that the reference signal information is the reference signal at the sampling period, and transmit the reply request signal indicating that the reference signal information is not the reference signal at timings other than the sampling period.

[0009] The reply request signal further includes control type information, and the signal transmitting unit may transmit the reply request signal in which the control type information indicates the type of control when instructing the second control device to perform control, and transmit the reply request signal in which the control type information indicates that there is no control to be instructed to the second control device at times other than when instructing the second control device to perform control.

[0010] The first control device and the second control device are configured to perform half-duplex communication via the synchronous communication line, and may also perform multi-bit asynchronous serial communication via the synchronous communication line.

[0011] The control system may have two or more of the second control devices.

[0012] A multi-axis testing machine according to one embodiment of the present invention has the control system described above. [Effects of the Invention]

[0013] This invention makes it possible to immediately stop the operation of a multi-axis testing machine in the event of an abnormality. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows a multi-axis testing machine according to one embodiment of the present invention. [Figure 2] This diagram illustrates an example of signal flow in a control system. [Figure 3] This diagram illustrates an example of signal flow in a control system. [Figure 4] This figure shows an example of the first control device 100. [Figure 5] This figure shows an example of the second control device 200. [Figure 6] This diagram illustrates an example of a reply request signal format. [Figure 7] This figure shows an example of communication in the control system according to this embodiment. [Modes for carrying out the invention]

[0015] <Multi-axis testing machine> Figure 1 shows a multi-axis testing machine according to one embodiment of the present invention. The multi-axis testing machine according to this embodiment tests, for example, the durability of a part against two or more axial loads. As shown in Figure 1, the multi-axis testing machine according to this embodiment has two or more actuators, and each of these two or more actuators applies, for example, one axial load to the part. In the example shown in Figure 1, the multi-axis testing machine has three actuators (actuator A1, actuator A2, actuator A3), but the number of actuators in the multi-axis testing machine according to this embodiment may be two or four or more. The axial load applied by each actuator may be compression, tension in one direction or both directions, vibration excitation, or axial rotational torsion, etc. Multi-axis testing machines capable of applying such loads include, but are not limited to, compression testing machines, tensile testing machines, vibration testing machines, torsion testing machines, etc.

[0016] The multi-axis testing machine according to this embodiment has two or more actuators and two or more control devices that correspond one-to-one with each other, with each of the two or more control devices controlling the corresponding actuator. These two or more control devices constitute a control system that controls the two or more corresponding actuators. Each of the two or more control devices has, for example, a computer (for example, an MPU (Micro Processor Unit)).

[0017] The control system according to this embodiment has two or more control devices, as shown in Figure 1, which include one first control device 100 and one or more second control devices 200, in order to synchronize the control of two or more actuators. In the example shown in Figure 1, there is one first control device 100 and two second control devices 200 (second control device 200A, second control device 200B), where the first control device 100 corresponds to actuator A1 and controls actuator A1, the second control device 200A corresponds to actuator A2 and controls actuator A2, and the second control device 200B corresponds to actuator A3 and controls actuator A3.

[0018] The multi-axis testing machine according to the present embodiment has two or more sets of actuators, and two or more sensors that have one-to-one correspondence with pairs of control devices. Each of the two or more sensors measures a physical quantity related to the corresponding actuator (for example, displacement or load), and inputs the measured value of the physical quantity to the corresponding control device. Then, in the multi-axis testing machine according to the present embodiment, each of the two or more control devices performs feedback control on the corresponding actuator based on the physical quantity measured by the corresponding sensor (that is, the sensor that measures the physical quantity related to the corresponding actuator). In the example shown in FIG. 1, the sensor S1 corresponds to the actuator A1 and the first control device 100, measures the physical quantity related to the actuator A1, and inputs the measurement of the physical quantity to the first control device 100; the sensor S2 corresponds to the actuator A2 and the second control device 200A, measures the physical quantity related to the actuator A2, and inputs the measurement of the physical quantity to the second control device 200A; the sensor S3 corresponds to the actuator A3 and the second control device 200B, measures the physical quantity related to the actuator A3, and inputs the measurement of the physical quantity to the second control device 200B. Then, in the example shown in FIG. 1, the first control device 100 performs feedback control on the actuator A1 based on the physical quantity measured by the sensor S1, the second control device 200A performs feedback control on the actuator A2 based on the physical quantity measured by the sensor S2, and the second control device 200B performs feedback control on the actuator A3 based on the physical quantity measured by the sensor S3.

[0019] As shown in Fig. 1, the control system according to the present embodiment includes a synchronous communication line SL, wherein the first control device 100 and one or more second control devices 200 are connected to this synchronous communication line SL via the communication line. That is, in the present embodiment, the first control device 100 and the one or more second control devices 200 are connected via this synchronous communication line SL. The control system according to the present embodiment is configured such that, for example, the first control device 100 and the one or more second control devices 200 can perform half-duplex communication via the synchronous communication line SL, and the first control device 100 and the one or more second control devices 200 perform multi-bit asynchronous serial communication via, for example, the synchronous communication line SL.

[0020] As shown in Figs. 2 and 3, each of the first control device 100 and the one or more second control devices 200 can transmit a signal to another control device by transmitting the signal to the synchronous communication line SL, and each of the first control device 100 and the one or more second control devices 200 can receive a signal transmitted to the synchronous communication line SL by another control device. In the example shown in Fig. 2, the signal (Signal 1) transmitted from the first control device 100 to the synchronous communication line SL is received from the synchronous communication line SL by the second control device 200A and the second control device 200B. In the example shown in Fig. 3, the signal (Signal 2) transmitted from the second control device 200A to the synchronous communication line SL is received from the synchronous communication line SL by the first control device 100 and the second control device 200B.

[0021] The control system according to the present embodiment is, for example, a so-called master-slave system, wherein the first control device 100 is a master and the second control device 200 is a slave. When the control system according to the present embodiment is a master-slave system, only the first control device 100 actively transmits signals to the synchronous communication line SL, and the second control device 200 does not actively transmit signals to the synchronous communication line SL. Only when receiving a signal requesting a reply from the first control device 100, the second control device 200 transmits a signal corresponding to the request to the synchronous communication line SL.

[0022] <Control System> Figure 4 shows an example of the first control device 100. The first control device 100 has a signal transmission unit 110. The signal transmission unit 110 of the first control device 100 transmits a signal to the synchronous communication line SL.

[0023] An abnormality may occur in the second control device 200 or in the actuators or sensors controlled by the second control device 200, necessitating the shutdown of the multi-axis testing machine (control system). In this embodiment, the signal transmission unit 110 transmits a reply request signal. The reply request signal is a signal for requesting a reply signal that includes information indicating whether or not a shutdown request has occurred in the second control device 200 (for example, a request to shut down the control system (shut down the multi-axis testing machine) due to an abnormality in the second control device 200 or in the actuators or sensors controlled by the second control device 200).

[0024] To prevent collisions of reply signals from two or more second control devices 200, in this embodiment, the signal transmission unit 110 transmits a reply request signal to each of the two or more second control devices 200 in sequence. At this time, the reply request signal includes information for identifying the second control device that is the target of the reply request (reply request target identification information). If the second control devices 200 are assigned node numbers, the reply request target identification information may be, for example, the node number.

[0025] Figure 5 shows an example of the second control device 200. The second control device 200 includes a signal receiving unit 210 and a reply signal transmitting unit 220.

[0026] The signal receiving unit 210 receives signals transmitted from other control devices to the synchronous communication line SL (for example, a reply request signal transmitted from the first control device 100) from the synchronous communication line SL.

[0027] In each of the two or more second control devices 200, if the target of the reply request identified in the reply request target identification information included in the reply request signal received by the signal receiving unit 210 is the second control device 200, the reply signal transmitting unit 220 transmits a reply signal to the synchronous communication line SL that includes information indicating whether or not a stop request has occurred in the second control device 200 (for example, a request to stop the control system (stop the multi-axis testing machine) due to an abnormality occurring in the second control device 200 or in the actuators or sensors controlled by the second control device 200).

[0028] As shown in Figure 4, the first control device 100 further includes a signal receiving unit 120. The signal receiving unit 120 receives signals transmitted from other control devices to the synchronous communication line SL (for example, a reply signal transmitted from the second control device 200) from the synchronous communication line SL.

[0029] In this embodiment, even if the control system has two or more second control devices 200, this reply signal is received by all control devices (the first control device 100 and the two or more second control devices 200). Therefore, in this embodiment, by periodically transmitting a reply request signal, all control devices (the first control device 100 and the two or more second control devices 200) can confirm whether or not a stop request has been issued to the second control device 200. When a stop request is issued to the first control device 100 or to the second control device 200, it is possible to immediately stop the operation of all control devices (the first control device 100 and the two or more second control devices 200) (i.e., the operation of the multi-axis testing machine). The reply signal may also include information for identifying the second control device 200 that sends the reply signal (reply device identification information (e.g., node number)).

[0030] To prevent collisions between the reply request signal from the first control device 100 and the reply signal from the second control device 200, the interval for transmitting the reply request signal is set to be longer than a first time. The first time is set so as not to collide with the reply request signal from the first control device 100 and the reply signal from the second control device 200, based on, for example, the data size of the reply request signal, the communication speed in the control system, and the processing time in the second control device 200.

[0031] Figure 6 illustrates an example of the format of a reply request signal. The reply request signal consists of a start bit, a stop bit, and eight data bits sandwiched in between, as shown in Figure 6. In this case, it is preferable to use five of the eight data bits to indicate the recipient of the reply request (for example, the node number of the recipient of the reply request), as shown in Figure 6.

[0032] <Synchronization of the control system> As shown in Figure 4, the first control device 100 further includes a clock generation unit 130 and a sampling clock generation unit 140.

[0033] The clock generation unit 130 generates a clock signal.

[0034] The sampling clock generation unit 140 generates a sampling clock signal based on the clock signal generated by the clock generation unit 130. The first control device 100 samples the measurement value from the corresponding sensor (sensor S1 in the example shown in Figure 1) based on the sampling clock signal generated by the sampling clock generation unit 140, and inputs a control signal to the corresponding actuator (actuator A1 in the example shown in Figure 1).

[0035] In this embodiment, the reply request signal is also used as a reference signal to inform the second control device 200 of the period (sampling period) of the sampling clock signal generated by the first control device 100. Therefore, in this embodiment, the reply request signal further includes information (reference signal information) indicating whether or not the reply request signal is a reference signal. The signal transmission unit 110 transmits a reply request signal at the sampling period, which is information indicating that the reference signal information is a reference signal, and transmits a reply request signal at timings other than the sampling period, which is information indicating that the reference signal information is not a reference signal.

[0036] The second control device 200 further includes a sampling clock generation unit 230, as shown in Figure 5. When the sampling clock generation unit 230 receives a reply request signal indicating that the reference signal information is a reference signal, it uses the reply request signal as the reference signal and generates a sampling clock signal based on the reference signal. Based on the sampling clock signal generated by the sampling clock generation unit 230, the second control device 200 samples the measured values ​​from the corresponding sensors (sensors S2 and S3 in the example shown in Figure 1) and inputs control signals to the corresponding actuators (actuators A2 and A3 in the example shown in Figure 1).

[0037] Furthermore, in this embodiment, the reply request signal is also used as a control signal to instruct the second control device 200 to perform controls such as starting or ending a test. Therefore, in this embodiment, the reply request signal includes control type information. When the signal transmission unit 110 of the first control device 100 instructs the second control device 200 to perform a control, it transmits a reply request signal in which the control type information indicates the type of control, and at times other than when it instructs the second control device 200 to perform a control, it transmits a reply request signal in which the control type information indicates that there is no control to be instructed to the second control device 200.

[0038] Therefore, in this embodiment, it is possible to send a reply request signal at the same time as the reference signal is sent or the control signal is sent. As a result, it is possible to send a reply request signal as frequently as possible, and when a stop request occurs in the second control device 200, it is possible to stop the operation of all control devices (the first control device 100 and two or more second control devices 200) (i.e., the operation of the multi-axis testing machine) more immediately.

[0039] If the reply request signal is 8-bit data as shown in Figure 6, for example, as shown in Figure 6, it is advisable to use one bit of the 8 data bits to indicate the reference signal information and two bits of the 8 data bits to indicate the control type information.

[0040] The signal transmission unit 110 of the first control device 100 may also transmit a reply request signal at the sampling period, which is information indicating that the reference signal information is not a reference signal, and that the control type information indicates that there is no control to be instructed to the second control device 200. In other words, the signal transmission unit 110 of the first control device 100 may also transmit a reply request signal at a timing that is neither the timing for transmitting the reference signal nor the timing for transmitting the control signal.

[0041] Figure 7 shows an example of communication in the control system according to this embodiment. In the example shown in Figure 7, the control system has two second control devices 200A and 200B. In the example shown in Figure 7, the first control device 100 transmits reply request signals to t=t1, t3, t5, t8, t10, t12, t14, and t16.

[0042] In this embodiment, the first control device 100 transmits a reply request signal to the two second control devices 200A and 200B, one by one, in sequence. In the example shown in Figure 7, the top column of the reply request signal transmitted by the first control device 100 indicates the reply request target identification information. A reply request signal with "A" in this column is a reply request signal transmitted to the second control device 200A, and a reply request signal with "B" in this column is a reply request signal transmitted to the second control device 200B. Also in the example shown in Figure 7, the top column of the reply signals transmitted by the second control devices 200A and 200B indicates the reply device identification information. A reply signal with "A" in this column is a reply signal transmitted from the second control device 200A, and a reply signal with "B" in this column is a reply signal transmitted from the second control device 200B.

[0043] In the example shown in Figure 7, the reply request signals transmitted at t=t1, t5, t10, and t14 are the reply request signals transmitted to the second control device 200A. After receiving these reply request signals, the second control device 200A transmits reply signals to t=t2, t7, t11, and t15. Then, the reply request signals transmitted at t=t3, t8, t12, and t16 are the reply request signals transmitted to the second control device 200B. After receiving these reply request signals, the second control device 200B transmits reply signals to t=t4, t9, t13, and t18.

[0044] Furthermore, in the example shown in Figure 7, the bottom column of the reply signal transmitted by the second control device 200 indicates whether or not a stop request has been generated in the second control device 200. A reply signal with "E" in this column indicates that a stop request has been generated in the second control device 200, while a reply signal with a blank column indicates that no stop request has been generated in the second control device 200.

[0045] In the example shown in Figure 7, the reply signal transmitted from the second control device 200A at t=t15 is a reply signal indicating that a stop request has been generated in the second control device 200A. After receiving this reply signal, the first control device 100, the second control devices 200A and 200B terminate the test at t=t18.

[0046] Furthermore, in the example shown in Figure 7, the second column from the top of the reply request signal transmitted by the first control device 100 indicates reference signal information. A reply request signal with "R" written in this column is a reference signal, while a reply request signal with a blank column is a non-reference signal.

[0047] In the example shown in Figure 7, the reply request signals sent at t=t1, t5, t10, t12, and t16 are reference reply request signals.

[0048] Furthermore, in the example shown in Figure 7, the bottom column of the reply request signal transmitted by the first control device 100 indicates the control type information. A reply request signal with "S" written in this column is a reply request signal that is a control signal for the start of a test, while a reply request signal with a blank column is a reply request signal that is not a control signal.

[0049] In the example shown in Figure 7, the reply request signal sent at t=t3 is a reply request signal which is a control signal for starting the test. After receiving this reply request signal, the first control device 100 and the second control devices 200A and 200B start the test at t=t6. In the example shown in Figure 7, the reply request signals sent at t=t8 and t14 are reply request signals which are neither reference signals nor control signals.

[0050] The present invention has been described above with reference to preferred embodiments. While the present invention has been described with specific examples, various modifications and changes can be made to these examples without departing from the spirit and scope of the invention as described in the claims. [Explanation of symbols]

[0051] 100 First control device 110 Signal transmission unit 120 Signal receiving unit 130 Clock generation unit 140 Sampling Clock Generation Unit 200 Second control device 210 Signal receiving unit 220 Reply signal transmission unit 230 Sampling Clock Generation Unit

Claims

1. A control system comprising a first control device and a second control device, The first control device and the second control device are connected via a synchronous communication line. The first control device is It has a signal transmission unit that transmits a reply request signal at a sampling period, The aforementioned reply request signal is, Includes reply request target identification information for identifying the second control device that is the subject of the reply request, The second control device is The signal receiving unit receives the aforementioned reply request signal, A control system having a reply signal transmitting unit that transmits a reply signal if the target of the reply request, identified by the reply request target identification information included in the reply request signal received by the signal receiving unit, is the second control device.

2. The aforementioned reply signal is, The control system according to claim 1, further comprising information indicating whether or not a stop request has occurred in the second control device that transmits the reply signal.

3. The aforementioned reply request signal is, The system further includes reference signal information indicating whether the reply request signal is a reference signal for informing the second control device of the sampling period, The signal transmission unit is At the sampling period, the reply request signal is transmitted to indicate that the reference signal information is the reference signal. The control system according to claim 2, wherein at a timing other than the sampling period, the system transmits the reply request signal indicating that the reference signal information is not the reference signal.

4. The aforementioned reply request signal is, Further includes control type information, The signal transmission unit is When instructing the second control device to perform control, the reply request signal is transmitted, the control type information being information indicating the type of control. The control system according to claim 3, wherein, at a time other than the timing for instructing the second control device to perform control, the system transmits the reply request signal, the control type information being information indicating that there is no control to be instructed to the second control device.

5. The first control device and the second control device are The system is configured to enable half-duplex communication via the aforementioned synchronous communication line. The control system according to claim 2, wherein multi-bit asynchronous serial communication is performed via the synchronous communication line.

6. The control system according to any one of claims 1 to 5, comprising two or more of the second control devices.

7. A multi-axis testing machine having the control system described in claim 6.

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