TWI847395B - Delay measurement device, delay measurement method, and recording medium storing delay measurement program - Google Patents

Abstract

Provide a delay measurement device capable of efficiently measuring the delay between nodes, etc.

The delay measurement device (1) includes a master node (3) and a slave node (4) connected in series with the master node (3). The master node (3) includes: a delay measurement frame sending unit (31) for sending a delay measurement frame including a return designation information of a slave node (4) designated as a return node for returning the received delay measurement frame; a delay measurement frame receiving unit (32) for receiving the delay measurement frame returned from the return node; and a delay measurement unit (33) for measuring the delay between the master node (3) and the return node according to the difference between the sending time of the delay measurement frame sent by the delay measurement frame sending unit (31) and the receiving time of the delay measurement frame received by the delay measurement frame receiving unit (32). The slave node (4) is provided with a delay measurement frame return unit (45), and the delay measurement frame return unit (45) returns the delay measurement frame received from the previous node to the previous node when the return designation information designates itself as the return node.

Description

Delay measurement device, delay measurement method, and recording medium storing delay measurement program

The present invention relates to a delay measurement device in a system having a master node and a slave node, etc.

Patent document 1 discloses a household appliance having a master node and a plurality of slave nodes connected in series with the master node and in a ring shape. Examples of slave nodes include sensors for measuring various operating parameters of household appliances and actuators for driving various parts of household appliances. These slave nodes communicate with the master node while performing coordinated actions, thereby realizing the desired actions of the household appliance.

[Prior Art Literature] [Patent Literature]

[Patent document 1] Japanese Patent Publication No. 8-280078

Unlike household appliances such as those in Patent Document 1, industrial systems used in industrial sites that produce products and provide services usually separately purchase relatively large industrial devices that constitute master nodes and slave nodes, and are mainly set up, connected, and configured manually in industrial sites. In order for each node to work in coordination, it is necessary to perform synchronization settings that take into account the delay caused by the wiring between nodes and the processing time of each node. In previous industrial systems, delayed measurements or calculations were performed manually, but the operating efficiency was poor and human errors were likely to occur.

The present invention was developed in view of this situation, and its purpose is to provide a delay measurement device that can efficiently measure the delay between nodes.

In order to solve the above problem, a delay measurement device of the present invention has a master node and one or more slave nodes connected in series with the master node. The master node has: a delay measurement frame sending unit, which sends a delay measurement frame including a return designation information of a slave node designated as a return node for returning the received delay measurement frame; a delay measurement frame receiving unit, which receives the delay measurement frame returned from the return node; and a delay measurement unit, which measures the delay between the master node and the return node according to the difference between the sending time of the delay measurement frame sent by the delay measurement frame sending unit and the receiving time of the delay measurement frame received by the delay measurement frame receiving unit. The slave node comprises: a return designation information confirmation unit, which confirms whether the return designation information contained in the delay measurement frame received from the adjacent previous node designates itself as a return node; a delay measurement frame return unit, which returns the delay measurement frame received from the previous node to the previous node when the return designation information designates itself as a return node; a downlink sending unit, which sends the delay measurement frame to the adjacent subsequent slave node when the return designation information does not designate itself as a return node; and an uplink sending unit, which sends the delay measurement frame returned from the subsequent slave node to the previous node.

According to this pattern, by sending a delay measurement frame from the master node, the delay between the slave node designated as the return node and the master node can be efficiently measured.

Another aspect of the present invention is a delay measurement method. In the method, a delay measurement frame including a slave node designated as a return node for returning a received delay measurement frame from one or more slave nodes connected in series with a master node is sent from the master node to an adjacent slave node at a subsequent stage, a slave node that is not a return node and receives a delay measurement frame from an adjacent node at a previous stage sends the delay measurement frame to an adjacent slave node at a subsequent stage, and a slave node that receives a delay measurement frame from an adjacent node at a previous stage sends the delay measurement frame to an adjacent slave node at a subsequent stage. The return node of the delay measurement frame returns the delay measurement frame to the node of the previous stage. The slave node that is not a return node and receives the delay measurement frame returned from the adjacent slave node of the subsequent stage sends the delay measurement frame to the adjacent node of the previous stage. The master node that receives the delay measurement frame returned from the adjacent slave node of the subsequent stage measures the delay between the master node and the return node based on the difference between the sending time and the receiving time of the delay measurement frame.

In addition, any combination of the above constituent elements, or the expression of the present invention converted between methods, devices, systems, recording media, computer programs, etc., is also valid as a form of the present computer program invention.

According to the present invention, the delay between nodes can be measured efficiently.

Below, referring to the drawings, the method for implementing the present invention is described in detail. In the description or drawings, the same or equivalent components, components, and processes are marked with the same symbols, and repeated descriptions are omitted. For the convenience of explanation, the scale and shape of each part of the diagram are appropriately set, and no restrictive interpretation is made unless otherwise specified. The implementation method is an example and does not limit the scope of the present invention in any way. All the features and combinations of the features described in the implementation method are not necessarily limited to the essence of the invention.

FIG. 1 is a functional block diagram of a delay measurement device 1 of an embodiment of the present invention. The delay measurement device 1 comprises: a master node 3; and one or more slave nodes 4, which are connected in series with the master node 3 in a linear or ring manner in a wired or wireless manner. In the illustrated example, three slave nodes 4A, 4B, and 4C having the same functional block groups 41 to 46 are provided, and are collectively referred to as slave nodes 4 except for the cases where they must be distinguished. The master node 3 and the slave nodes 4 are respectively provided in the same or different industrial devices, and constitute an industrial system as a whole. Therefore, it can be said that the delay measurement device 1 is provided in an industrial system. One or more slave nodes 4 communicate with the master node 3 and perform coordinated actions, thereby realizing the desired actions of the industrial system and the delay measurement device 1.

Industrial equipment provided with master node 3 and slave node 4 is an equipment used for a predetermined purpose in an industrial field that produces various products and provides various services. Specific examples of industrial equipment will be described later, but include boilers and engines used by The Japan Society Of Industrial Machinery Manufacturers, mining machinery, chemical machinery, environmental protection equipment, tanks, plastic machinery, wind power or hydraulic machinery, handling machinery, power transmission equipment, iron smelting machinery, commercial washing machines, etc., industrial machinery used in industrial fields such as factories of enterprises, industrial machinery, industrial equipment, etc., manufacturing equipment for semiconductors, etc., machine tools, printing machines, and industrial robots. In addition, general-purpose devices such as personal computers and smart phones used for monitoring and controlling these devices are also equivalent to industrial devices in the context of this embodiment.

The master node 3 and/or the slave node 4 may correspond to the entire industrial device or to each part (e.g., each component) of the industrial device. As an example of the latter, the master node 3 may be composed of a controller of the industrial device, and the slave node 4 may be composed of a driver that drives a motor inside or outside the industrial device according to instructions from the controller, and a sensor that measures various operating parameters inside or outside the industrial device and provides them to the controller.

The driver constituting slave node 4 drives the motors for driving the movable parts of the industrial device itself (e.g., the joints of the industrial robot, the processing parts of the machine tool, the platform for placing the processed objects), the relays (relays) for controlling the movements of the various parts of the industrial device, and the motors for controlling the movable parts of the parts such as solenoid valves. In the case where the industrial device is a motor driver, the driven motor is installed outside the industrial device (slave node 4). The sensors constituting the slave node 4 are, for example, sensors for measuring the position, speed, acceleration, etc. of a driven object driven by a driver constituting another slave node 4 (for example, a carrier in a machine tool, a web fed from a rotary printing press), sensors for measuring other motion parameters of the driven object (for example, the tension of the web, the pressure applied from the roller), and sensors for measuring motion parameters related to the environment in which the industrial equipment operates (for example, temperature, humidity, air pressure, brightness).

In addition, part or all of the master node 3 and each slave node 4A, 4B, 4C can be set up in different industrial sites, or in offices, data centers, etc. that are separated from the industrial sites. In addition, the function blocks of the master node 3 and each slave node 4A, 4B, 4C are implemented by the cooperation of the hardware resources such as the central processing unit, memory, input device, output device, and peripheral devices connected to the computer and the software executed using the same. Regardless of the type and location of the computer, the above-mentioned function blocks can be implemented by the hardware resources of a single computer, or by combining the hardware resources distributed in a plurality of computers. For example, part or all of the functional blocks of the master node 3 and each slave node 4A, 4B, 4C may be implemented by a computer located outside the industrial device or outside the industrial site.

The master node 3 includes a delay measurement frame sending unit 31, a delay measurement frame receiving unit 32, and a delay measurement unit 33. Each slave node 4 includes a delay measurement frame receiving unit 41, a return specified information confirmation unit 42, a downlink sending unit 43, an identification information writing unit 44, a delay measurement frame returning unit 45, and an uplink sending unit 46.

The delay measurement frame sending unit 31 sends the delay measurement frame 5 including the return designation information 54 to the adjacent subsequent slave node 4A. The return designation information 54 specifies a slave node 4 among the plurality of slave nodes 4A, 4B, 4C as a return node that returns the delay measurement frame 5 received by the delay measurement frame receiving unit 41 through the delay measurement frame return unit 45.

FIG2 shows an example of a delay measurement frame 5. The 46-byte fixed-length delay measurement frame 5 has a 1-byte frame number 51, a 1-byte frame type 52, a 2-byte connection state information 53, a 2-byte return designation information 54, a 2-byte identification information write field 55, a 36-byte virtual field 56, and a 2-byte error notification field 57. In addition, the frame length of the delay measurement frame 5 and the field lengths of each information 51 to 57 can be appropriately changed according to the communication protocol of the industrial system.

The frame number 51 is a number assigned by the master node 3 to the delay measurement frame 5. The frame class 52 is information indicating the class of the frame, and a unique number (for example, "17" in decimal) assigned to the delay measurement frame as the class is written. The connection pattern information 53 is information indicating the connection pattern of the slave node 4, and for example, it is information indicating either a linear pattern or a ring pattern. In the example of FIG1 , the slave node 4 is connected to the master node 3 in a linear pattern.

The return designation information 54 is information for designating a slave node 4 to be a return node among a plurality of slave nodes 4A, 4B, and 4C. In the example of FIG. 1 where the third slave node 4C is designated as the return node, "3" is written as a decimal number. The identification information writing field 55 is a field in which the slave node 4C designated as the return node can write its own identification information (for example, "3" as its own node number) when the delay measurement frame return unit 45 returns the delay measurement frame 5 received by the delay measurement frame receiving unit 41.

Virtual data consisting of, for example, 36 "0"s are written into the virtual field 56. The virtual data is meaningless data that is not used in the processing of the delay measurement frame 5, but is inserted to maintain the length of the delay measurement frame 5 at 46 bytes, which is the same as the communication frame used for communication between the nodes 3 and 4. As a result, the time for each slave node 4 to process the delay measurement frame 5 (46 bytes) is roughly equal to the time for each slave node 4 to process the communication frame (46 bytes) when the industrial system is operating normally, so that the internal processing time of each slave node 4 can be accurately simulated and the delay between nodes can be measured with high accuracy. In the error notification field 57, a frame check sequence (FCS: Frame Check Sequence) for error detection during communication of the delayed measurement frame 5 is written.

The delay measurement frame receiving unit 41 of the slave node 4A receives the delay measurement frame 5 from the master node 3 which is the adjacent previous node. The return designation information confirmation unit 42 confirms whether the return designation information 54 included in the delay measurement frame 5 received from the master node 3 designates itself (the slave node 4A) as the return node. In this example, the slave node 4C is designated as the return node, so the return designation information confirmation unit 42 of the slave node 4A confirms that it is not designated as the return node. Based on the confirmation result, the downlink sending unit 43 resends the delay measurement frame 5 received by the delay measurement frame receiving unit 41 from the master node 3 to the adjacent subsequent slave node 4B.

The delay measurement frame receiving unit 41 of the slave node 4B receives the delay measurement frame 5 from the slave node 4A which is the adjacent previous node. The return designation information confirmation unit 42 confirms whether the return designation information 54 included in the delay measurement frame 5 received from the slave node 4A designates itself (the slave node 4B) as the return node. In this example, the slave node 4C is designated as the return node, so the return designation information confirmation unit 42 of the slave node 4B confirms that it is not designated as the return node. Based on the confirmation result, the downlink sending unit 43 resends the delay measurement frame 5 received by the delay measurement frame receiving unit 41 from the slave node 4A to the adjacent subsequent slave node 4C.

The delay measurement frame receiving unit 41 of the slave node 4C receives the delay measurement frame 5 from the slave node 4B which is the adjacent previous node. The return designation information confirmation unit 42 confirms whether the return designation information 54 included in the delay measurement frame 5 received from the slave node 4B designates itself (the slave node 4C) as a return node. In this example, the slave node 4C is designated as a return node, so the return designation information confirmation unit 42 of the slave node 4C confirms that it is designated as a return node. Based on the confirmation result, the identification information writing unit 44 writes its own identification information as a return node (for example, "3" as its own node number) into the identification information writing field 55 of the delay measurement frame 5 received from the slave node 4B. The delay measurement frame returning unit 45 returns the delay measurement frame 5 into which the identification information of the slave node 4C (returning node) is written by the identification information writing unit 44 to the adjacent previous-stage slave node 4B.

The uplink transmission unit 46 of the slave node 4B retransmits the delay measurement frame 5 returned from the adjacent subsequent slave node 4C (delay measurement frame return unit 45) to the adjacent previous slave node 4A. The uplink transmission unit 46 of the slave node 4A retransmits the delay measurement frame 5 returned from the adjacent subsequent slave node 4B (uplink transmission unit 46) to the adjacent previous master node 3. The delay measurement frame receiving unit 32 of the master node 3 receives the delay measurement frame 5 from the adjacent subsequent slave node 4A (uplink transmission unit 46). The master node 3 can confirm that the round-trip communication of the delay measurement frame 5 between the master node 3 and the return node (slave node 4C) is carried out normally by writing the identification information of the return node (slave node 4C) into the identification information write field 55 of the delay measurement frame 5 received by the delay measurement frame receiving unit 32.

The delay measurement unit 33 of the master node 3 measures the delay between the master node 3 and the return node (slave node 4C) according to the difference between the sending time of the delay measurement frame 5 sent by the delay measurement frame sending unit 31 and the receiving time of the delay measurement frame 5 received by the delay measurement frame receiving unit 32. Specifically, the counter 331 provided in the delay measurement unit 33 starts counting when the delay measurement frame 5 is sent by the delay measurement frame sending unit 31, and stops counting when the delay measurement frame 5 is received by the delay measurement frame receiving unit 32. The count value is equivalent to the round-trip delay time (expressed as 2T _1~3 ) between the master node 3 and the return node (slave node 4C). Therefore, the delay calculation unit 332 provided in the delay measurement unit 33 is divided by 2 to obtain the delay T _1~3 between the master node 3 and the return node (slave node 4C).

The delay _T1-3 between the master node 3 and the slave node 4C is the sum of the delay _T1 between the mutually adjacent master node 3 and the slave node 4A, the delay _T2 between the mutually adjacent slave nodes 4A and 4B, and the delay _T3 between the mutually adjacent slave nodes 4B and 4C ( _T1-3 = _T1 + _T2 + _T3 ). Furthermore, the delay _T1 between the master node 3 and the slave node 4A is the sum of the transmission delay _L1 caused by the wiring between the master node 3 and the slave node 4A and the internal processing time _P1 of the slave node 4A ( _T1 = _L1 + _P1 ), the delay _T2 between the slave node 4A and the slave node 4B is the sum of the transmission delay _L2 caused by the wiring between the slave node 4A and the slave node 4B and the internal processing time _P2 of the slave node 4B ( _T2 = _L2 + _P2 ), and the delay _T3 between the slave node 4B and the slave node 4C is the sum of the transmission delay _L3 caused by the wiring between the slave node 4B and the slave node 4C and the internal processing time _P3 of the slave node 4C ( _T3 = _L3 +P ₃ ).

The delay measurement frame sending unit 31 of the master node 3 sequentially sends the delay measurement frame 5 including the return designation information 54 for sequentially designating all the connected slave nodes 4A, 4B, and 4C as return nodes. For example, as shown in FIG1 , after designating the slave node 4C as the return node and measuring the delay T _1~3 (T ₁ +T ₂ +T ₃ ) between the master node 3 and the slave node 4C, the slave node 4B is designated as the return node and the delay T _1~2 (T ₁ +T ₂ ) between the master node 3 and the slave node 4B is measured, and then the slave node 4A is designated as the return node and the delay T ₁ between the master node 3 and the slave node 4A is measured. The delay calculation unit 332 calculates the delays _T1, T2, and T3 between adjacent nodes according to the sequentially measured T1-3 ( _T1 + _T2 + _T3 ), _T1-2 ( _T1 + _T2 ), and _T1 . Specifically, in addition to the delay _T1 between the master node 3 and the slave node 4A directly obtained by measurement _, the delay _T2 between the slave node 4A and the slave node 4B is also obtained by _{T1-2 - T1} , and _the delay _T3 between the slave node 4B and the slave node 4C is also obtained by _{T1-3- T1-2} .

In addition, unlike FIG. 1 in which the slave node 4 and the master node 3 are connected in a line, in the case where the slave node 4 and the master node 3 are connected in a ring, for example, in the case where the slave node 4C is directly connected to the master node 3 at the downstream stage, the master node 3 may not designate the slave node 4C as a return node. At this time, the downlink transmission unit 43 of the slave node 4C directly transmits the delay measurement frame 5 received by the delay measurement frame receiving unit 41 to the master node 3 (delay measurement frame receiving unit 32). At this time, the delay measured by the delay measurement unit 33 (counter 331) of the master node 3 becomes the delay _L4 caused by the wiring between the slave node 4C and the master node 3, etc., added to T1 _~3 . Furthermore, when the slave node 4 and the master node 3 are connected in a ring, the master node 3 can send the delay measurement frame 5 in the opposite direction to Figure 1. For example, the delay measurement frame sending unit 31 of the master node 3 can also send the delay measurement frame 5 to the adjacent slave node 4C instead of the slave node 4A.

FIG3 is a flow chart of the delay measurement process performed by the delay measurement device 1. "S" in the description of the flow chart represents a step or a process. In S1, the delay measurement frame sending unit 31 of the master node 3 sends the delay measurement frame 5 to the adjacent subsequent slave node 4A. In S2, the delay measurement frame receiving unit 41 of the slave node 4 receives the delay measurement frame 5 from the adjacent previous node. In S3 and S4, the return designation information confirmation unit 42 confirms whether the return designation information 54 included in the delay measurement frame 5 received in S2 designates itself as a return node. If the answer is "No" in S4, the process proceeds to S5, and the downlink transmission unit 43 retransmits the delay measurement frame 5 received in S2 to the adjacent subsequent slave node 4. The adjacent subsequent slave node 4 receives the delay measurement frame 5 retransmitted in S5 in S2.

If the answer is yes in S4, the process proceeds to S6, and the identification information writing unit 44 writes the identification information of the return node into the identification information writing field 55 of the delay measurement frame 5 received in S2. In S7, the delay measurement frame returning unit 45 of the slave node 4, which is the return node, returns the delay measurement frame 5 in which the identification information is written in S6 to the adjacent previous node, or the uplink sending unit 46 of the slave node 4, which is not the return node, resends the delay measurement frame 5 returned from the adjacent subsequent slave node 4 to the adjacent previous node. In S8, the delay measurement frame receiving unit 32 of the master node 3 receives the delay measurement frame 5 from the adjacent subsequent slave node 4A. In S9, the counter 331 of the delay measurement unit 33 measures the delay between the master node 3 and the return node according to the difference between the sending time of the delay measurement frame 5 in S1 and the receiving time of the delay measurement frame 5 in S8.

In S10, it is determined whether all slave nodes 4A, 4B, and 4C connected to the master node 3 are designated as return nodes. If the answer is no in S10, the process proceeds to S11, and the undesignated slave node 4 is designated as a return node. In the subsequent S1, the delay measurement frame sending unit 31 sends the delay measurement frame 5 including the return designation information 54 designating the slave node 4 designated in S11 as a return node to the adjacent subsequent slave node 4A. If the answer is yes in S10, the process proceeds to S12, where the delay calculation unit 332 of the delay measurement unit ₃₃ calculates the delays _T1 , T2, _{and T3} between adjacent nodes according to T1-3 ( _T1 + _T2 + _T3 ), _{T1-2 ( T1} + _T2 ), and _T1 measured in sequence in S9.

The above delay measurement device 1 can be used in any industrial system.

FIG4 is a perspective view showing the overall structure of a linear transport system 100 as an example of an industrial system. The linear transport system 100 includes: a stator 200, which forms an annular guide rail or track; and a plurality of movable parts 300A, 300B, 300C, and 300D (hereinafter collectively referred to as movable parts 300), which are driven relative to the stator 200 and can move along the guide rail. By the electromagnet or coil provided on the stator 200 and the permanent magnet provided on the movable part 300 facing each other, a linear motor is formed along the annular guide rail. For example, the linear motor and the driver driving it constitute the slave node 4 in FIG1. Furthermore, a sensor for measuring the position, velocity, acceleration, temperature, humidity, air pressure, etc. of the movable part 300 driven by the actuator, and the surrounding linear transport system 100 may be provided as the slave node 4 in FIG. 1. The master node 3 capable of communicating with the slave nodes 4 is provided in a controller (not shown) of the linear transport system 100. In addition, a permanent magnet may be provided in the stator 200, and an electromagnet or a coil may be provided in the movable part 300.

The guide rail formed by the stator 200 can be any shape not limited to a ring shape. For example, the guide rail can be straight or curved, one guide rail can be branched into multiple guide rails, and multiple guide rails can be merged into one guide rail. In addition, the setting direction of the guide rail formed by the stator 200 is also arbitrary. In the example of FIG. 4, the guide rail is arranged in a horizontal plane, but the guide rail can also be arranged in a straight surface, or in a plane with an arbitrary inclination angle or in a curved surface.

The stator 200 has a rail surface 210 with the horizontal direction as the normal direction. The rail surface 210 extends in a band shape along the direction in which the rail is formed, and in the case of forming a ring-shaped rail as in the example of FIG. 4 , forms a ring-shaped band shape by connecting (imaginary) two ends. As described above, a plurality of electromagnets (not shown) are continuously or periodically buried in the rail surface 210 of the rail that can form any shape. If a three-phase AC or other driving current flows through the plurality of electromagnets of the linear motor under the control of a controller (master node 3) not shown, a moving magnetic field is generated that linearly drives the movable part 300 having a permanent magnet in the desired tangential direction along the rail. In the example of FIG. 4 , the normal direction of the guide rail surface 210 in which the annular guide rail is formed in a horizontal plane is the horizontal direction, but the normal direction of the guide rail surface 210 may be the vertical direction or any other direction.

In the stator 200, a plurality of magnetic positioning devices (not shown) capable of measuring the position of a magnetic scale (not shown) mounted on the movable part 300 as a positioning object are continuously or periodically embedded in the positioning portion 220 disposed on the upper surface or the lower surface perpendicular to the guide rail surface 210. A magnetic positioning device that uses a magnetic scale formed by a striped magnetic pattern with a certain pitch as a positioning object usually has a plurality of magnetic detection heads. By staggering the intervals between the plurality of magnetic detection heads relative to the pitch or period of the magnetic pattern of the magnetic scale, the magnetic positioning device can measure the position of the magnetic scale with high precision. In a typical magnetic position measuring device having two magnetic detection heads, for example, the interval between the two magnetic detection heads is shifted by 1/4 pitch (phase shifted by 90 degrees) relative to the magnetic pattern of the magnetic scale.

In addition, the positioning device installed on the stator 200 and the positioning object installed on the movable part 300 are not limited to the magnetic type as described above, and can also be optical or other methods. In the case of the optical type, an optical scale formed by a stripe pattern with a certain spacing is installed on the movable part 300, and an optical positioning device capable of optically reading the stripe pattern of the optical scale is installed on the stator 200. In the magnetic type and the optical type, the positioning device measures the positioning object (magnetic scale, optical scale) in a non-contact manner, thereby reducing the risk of failure of the positioning device when the transported object transported by the movable part 300 splashes and enters the positioning part (the upper surface of the stator 200). Among them, in the optical method, if the transported object such as liquid or powder that enters the positioning part covers the optical scale, the positioning accuracy will deteriorate. Therefore, if the magnetism of the transported object can be ignored, it is better to use the magnetic method because even if the transported object enters the positioning part, the positioning accuracy will not deteriorate.

The movable part 300 includes: a movable part body 310, which is opposite to the guide rail surface 210 of the stator 200; a position-detected part 320, which extends horizontally from the upper part of the movable part body 310 and is opposite to the position-detected part 220 of the stator 200; and a transport part 330, which extends horizontally from the movable part body 310 on the side opposite to the position-detected part 320 (the side far from the stator 200) and carries or fixes the transported object. The movable part body 310 includes one or more permanent magnets (not shown) that are opposite to the plurality of electromagnets buried in the guide rail surface 210 of the stator 200 along the guide rail. The moving magnetic field generated by the electromagnetic magnet of the stator 200 applies a linear force in the tangential direction of the guide rail to the permanent magnet of the movable element 300, so that the movable element 300 is linearly driven along the guide rail surface 210 relative to the stator 200.

A magnetic scale and an optical scale as a positioning target are provided on the positioning target portion 320 of the movable member 300 so as to face the positioning device provided on the positioning target portion 220 of the stator 200. In the example of FIG. 4 in which the positioning device is provided on the upper surface of the stator 200, the positioning target such as the magnetic scale is mounted on the lower surface of the positioning target portion 320 of the movable member 300. When the positioning part 220 and the part to be positioned 320 are magnetic, the guide surface 210 and the positioning part 220 are formed on different surfaces or separate parts in the stator 200, and the movable part body 310 and the part to be positioned 320 are formed on different surfaces or separate parts in the movable part 300, so that the magnetic field between the electromagnetic iron of the guide surface 210 and the permanent magnet of the movable part body 310 does not affect the magnetic positioning of the positioning part 220 and the part to be positioned 320.

FIG5 shows the structure of a printing device 10 as an example of an industrial system. The printing device 10 includes a first printing unit 11A for printing black (K), a second printing unit 11B for printing cyan (C), a third printing unit 11C for printing magenta (M), a fourth printing unit 11D for printing yellow (Y), and a (registration) control device 30 provided with the main node 3 in FIG1. Hereinafter, the first printing unit 11A to the fourth printing unit 11D are collectively referred to as printing units 11. In addition, the printing colors of each printing unit 11 are not limited to the above, and any printing colors can be assigned to each printing unit 11 in any order. Moreover, in order to print more colors, more than five printing units can be provided.

The first printing unit 11A includes a first plate cylinder 13A, a first impression cylinder 17A, a first drive motor 19A, a first encoder 21A, and a first mark sensor 23A. The second printing unit 11B includes a second plate cylinder 13B, a second impression cylinder 17B, a second drive motor 19B, a second encoder 21B, and a second mark sensor 23B. The third printing unit 11C includes a third plate cylinder 13C, a third impression cylinder 17C, a third drive motor 19C, a third encoder 21C, and a third mark sensor 23C. The fourth printing unit 11D includes a fourth plate cylinder 13D, a fourth impression cylinder 17D, a fourth drive motor 19D, a fourth encoder 21D, and a fourth mark sensor 23D. Hereinafter, the first plate cylinder 13A to the fourth plate cylinder 13D are collectively referred to as the plate cylinder 13, the first impression cylinder 17A to the fourth impression cylinder 17D are collectively referred to as the impression cylinder 17, the first drive motor 19A to the fourth drive motor 19D are collectively referred to as the drive motor 19, the first encoder 21A to the fourth encoder 21D are collectively referred to as the encoder 21, and the first mark sensor 23A to the fourth mark sensor 23D are collectively referred to as the mark sensor 23.

The printing device 10 prints on a roll paper, i.e., a coil 50, as a printed object. Each printing unit 11 is arranged along the moving direction of the coil 50. The coil 50 is guided by a guide roller 25 arranged along its moving path, and the printing plate cylinder 13 and the impression cylinder 17 of each printing unit 11 sequentially print patterns of each color corresponding to the brush plate wound on the printing plate cylinder 13.

The plate drum 13 has a mark printing section 15, which prints a mark measured by a mark sensor 23 for registration control. The mark printing section 15 of the first printing unit 11A also prints a reference mark when the same web 50 is followed by printing. The reference mark sometimes also indicates the cutting position of the web 50 after printing, and is also called a cutting mark. The first mark is printed by the mark printing section 15 of the first plate drum 13A at a predetermined first position, the second mark is printed by the mark printing section 15 of the second plate drum 13B at a predetermined second position, the third mark is printed by the mark printing section 15 of the third plate drum 13C at a predetermined third position, and the fourth mark is printed by the mark printing section 15 of the fourth plate drum 13D at a predetermined fourth position. Hereinafter, the 1st to 4th imprints are collectively referred to as imprints.

The circumference of each plate cylinder 13 is the same, and each printing unit 11 prints a copy of each color pattern by rotating each plate cylinder 13 once, and printing is performed repeatedly and continuously. Each plate cylinder 13 is rotationally driven by a separate drive motor 19 controlled by a motor driver constituting the slave node 4 in Figure 1. During the printing operation of the printing device 10, each drive motor 19 rotates electrically and synchronously through the motor driver (slave node 4) under the control of the control device 30 (master node 3), and each plate cylinder 13 rotates at the same rotation speed. That is, the printing device 10 is constructed in a segmented drive manner. The encoder 21 constituting the slave node 4 in Figure 1 is set on the mechanical shaft of each drive motor 19.

The encoder 21 is an incremental encoder. Each time the plate drum 13 rotates once, the encoder 21 outputs a predetermined number of A-phase and B-phase pulse signals and one Z-phase pulse signal. The A-phase and B-phase pulse signals are counted by a counter, and the count value is reset by the Z-phase pulse signal. The phase (rotational position) of the plate drum 13 is detected based on the count value of the pulse signal. In addition, as long as the encoder 21 can detect the phase of the plate drum 13, it can be an absolute serial encoder regardless of the method. In addition, in addition to the encoder 21 and mark sensor 23 constituting the slave node 4 in Figure 1, a sensor for measuring the position, speed, acceleration of the printing plate drum 13 and the web 50 driven by the drive motor 19 (as the motor driver of the slave node 4), the pressure applied by the stamping drum 17 to the web 50, the tension of the web 50, the temperature, humidity, air pressure, brightness, etc. around the printing device 10 can also be set as the slave node 4.

The present invention has been described above based on the embodiments. Those skilled in the art should understand that the embodiments are examples, and various modifications can be applied to the combination of the components and the processing steps, and such modifications are also within the scope of the present invention.

In addition, the functional configuration of each device described in the implementation method can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. As hardware resources, processors, ROM, RAM, and other LSIs can be used. As software resources, programs such as operating systems and applications can be used. This application claims priority based on Japanese patent application No. 2021-195352 filed on December 1, 2021. The entire contents of the Japanese application are cited in this specification by reference.

1: Delay measurement device 3: Master node 4: Slave node 5: Delay measurement frame 31: Delay measurement frame sending unit 32: Delay measurement frame receiving unit 33: Delay measurement unit 41: Delay measurement frame receiving unit 42: Return designated information confirmation unit 43: Downlink transmission unit 44: Identification information writing unit 45: Delay measurement frame return unit 46: Uplink transmission unit 54: Return designated information 55: Identification information writing unit 331: Counter 332: Delay operation unit

[Figure 1] is a functional block diagram of a delay measurement device. [Figure 2] shows an example of a delay measurement frame. [Figure 3] is a flow chart of a delay measurement process performed by a delay measurement device. [Figure 4] is a three-dimensional diagram showing the overall structure of a linear transport system as an example of an industrial system. [Figure 5] shows the structure of a printing device as an example of an industrial system.

1: Delay measurement device

3: Master node

4,4A,4B,4C: From the node

31: Delay measurement frame sending unit

32: Delay measurement frame receiving unit

33: Delay measurement department

41: Delay measurement frame receiving unit

42: Return to designated information confirmation department

43: Downlink transmission unit

44: Identification information writing department

45: Delay measurement frame return unit

46: Uplink transmission unit

331:Counter

332: Delayed operation unit

Claims (9)

A delay measurement device comprises a master node and one or more slave nodes connected in series with the master node, wherein the master node comprises: a delay measurement frame sending unit, which sends a delay measurement frame including a return designation information of a slave node designated as a return node for returning the received delay measurement frame; a delay measurement frame receiving unit, which receives the delay measurement frame returned from the return node; and a delay measurement unit, which measures the delay between the master node and the return node according to the difference between the sending time of the delay measurement frame sent by the delay measurement frame sending unit and the receiving time of the delay measurement frame received by the delay measurement frame receiving unit, wherein the slave node It is provided with: a return designation information confirmation unit, which confirms whether the aforementioned return designation information contained in the aforementioned delay measurement frame received from the adjacent previous node designates itself as a return node; a delay measurement frame return unit, which returns the aforementioned delay measurement frame received from the aforementioned previous node to the previous node when the aforementioned return designation information designates itself as a return node; a downlink sending unit, which sends the aforementioned delay measurement frame to the adjacent subsequent slave node when the aforementioned return designation information does not designate itself as a return node; and an uplink sending unit, which sends the aforementioned delay measurement frame returned from the aforementioned subsequent slave node to the aforementioned previous node. The delay measurement device as described in claim 1, wherein the delay measurement frame sending unit sequentially sends delay measurement frames including return designation information for sequentially designating all slave nodes connected in series with the master node as return nodes, and the delay measurement unit measures the delay between the master node and each of the slave nodes according to the difference between the sending time of each of the delay measurement frames sent by the delay measurement frame sending unit and the receiving time of each of the delay measurement frames received by the delay measurement frame receiving unit. The delay measurement device as described in claim 2 further comprises: a delay calculation unit, which calculates the delay between adjacent nodes based on the delay between the aforementioned master node and the aforementioned slave nodes measured by the aforementioned delay measurement unit. A delay measurement device as described in any one of claim 1 to claim 3, wherein the delay measurement unit has a counter, and the counter starts counting when the delay measurement frame sending unit sends the delay measurement frame, and stops counting when the delay measurement frame receiving unit receives the delay measurement frame. A delay measurement device as described in any one of claim 1 to claim 3, wherein the delay measurement frame includes an identification information write-in field capable of writing its own identification information when the return node returns the delay measurement frame. A delay measurement device as described in any one of claim 1 to claim 3, wherein the length of the delay measurement frame is the same as the communication frame used for communication between nodes. A delay measurement device as described in any one of claim 1 to claim 3, wherein at least one of the aforementioned master node and the aforementioned slave node is disposed in an industrial device. A delay measurement method, which includes designating one or more slave nodes connected in series with a master node as a return node for returning a received delay measurement frame, sending a delay measurement frame of return designated information from the master node to an adjacent slave node of a subsequent stage, a slave node that is not a return node and receives the delay measurement frame from an adjacent node of a previous stage sends the delay measurement frame to an adjacent slave node of a subsequent stage, and a slave node that receives the delay measurement frame from an adjacent node of a previous stage sends the delay measurement frame to an adjacent slave node of a subsequent stage. Before the delay measurement frame, the return node returns the delay measurement frame to the node of the previous stage. After receiving the delay measurement frame returned from the adjacent slave node of the next stage, the slave node that is not the return node sends the delay measurement frame to the adjacent node of the previous stage. Before receiving the delay measurement frame returned from the adjacent slave node of the next stage, the master node measures the delay between the master node and the return node according to the difference between the sending time and the receiving time of the delay measurement frame. A recording medium storing a delay measurement program, wherein a delay measurement frame including a slave node designated as a return node for returning a received delay measurement frame from one or more slave nodes connected in series with a master node is sent from the master node to an adjacent slave node at a subsequent stage, and a slave node that is not a return node and receives the delay measurement frame from an adjacent node at a previous stage sends the delay measurement frame to an adjacent slave node at a subsequent stage, and a slave node that receives the delay measurement frame from an adjacent node at a previous stage receives the delay measurement frame from an adjacent node at a previous stage. Before the aforementioned delay measurement frame is sent, the return node sends the delay measurement frame back to the node at the previous stage, so that the slave node that is not a return node and receives the delay measurement frame sent back from the adjacent slave node at the next stage sends the delay measurement frame to the adjacent node at the previous stage, so that before the aforementioned master node receives the delay measurement frame sent back from the adjacent slave node at the next stage, the master node measures the delay between the master node and the aforementioned return node according to the difference between the sending time and the receiving time of the delay measurement frame.

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