Remote control system

Abstract

To enable disturbance compensation by separating a communication delay disturbance and a processing delay disturbance, in a remote control system via a communication network.SOLUTION: The present disclosure provides a remote control device including a measurement data receiving unit that receives measurement data measured by a control object from the control object, a metadata receiving unit that receives a measurement time of the measurement data in the control object, a processing delay disturbance calculation unit that calculates a processing delay disturbance included in the measurement data received by the measurement data receiving unit based on the measurement time, a communication delay disturbance calculation unit that calculates a communication delay disturbance included in the measurement data received by the measurement data receiving unit, and a disturbance compensation unit that compensates for the processing delay disturbance and the communication delay disturbance in the measurement data using the processing delay disturbance and the communication delay disturbance.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a technique for compensating for processing delays and communication delays in a remote control system. [Background technology]

[0002] In remote feedback control of actuators such as motors via a communication network, communication delays and processing delays adversely affect the stability and performance of the system. Techniques for compensating for communication delays and processing delays have been proposed, including a Smith predictor using a constant communication delay model, an adaptive Smith predictor using an adaptive communication delay model based on RTT (Round-Trip Time) measurements, and a communication disturbance observer (CDOB) that does not require a communication delay model (see, for example, Non-Patent Documents 1 and 2). It has been suggested that filter design according to the characteristics of communication delays is particularly important for CDOBs (see, for example, Non-Patent Document 3).

[0003] Conventional CDOB does not distinguish between the effects of communication delays and processing delays, but estimates and compensates for them collectively as disturbances on the system. However, conventional CDOB has the problem of being unable to separately estimate and compensate for communication delay disturbances and processing delay disturbances. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Kenji Natori, Roberto Oboe, and Kouhei Ohnishi, “Stability analysis and practical design procedure of time delayed control systems with communication disturbance observer,” IEEE Transactions on Industrial Informatics, vol. 4, no. 3, pp. 185-197, Aug. 2008. [Non-patent document 2] Ryogo Kubo and Kenji Natori, “Dependable networked motion control using communication disturbance observer,” Proceedings of the 27th International Technical Conference on Circuits / Systems, Computers and Communications (ITC-CSCC), D-T1-05, pp. 1-4, July 2012. [Non-patent document 3] Kenji Natori and Kouhei Ohnishi, “A design method of communication disturbance observer for time-delay compensation, taking the dynamic property of network disturbance into account,” IEEE Transactions on Industrial Electronics, vol. 55, no. 5, pp. 2152-2168, May 2008. Summary of the Invention [Problem to be solved by the invention]

[0005] Because communication delays and processing delays have different effects on system stability and performance, it is desirable to compensate for system disturbances caused by communication delays (communication delay disturbances) and system disturbances caused by processing delays (processing delay disturbances) by applying different filter processing.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to enable disturbance compensation by separating communication delay disturbance and processing delay disturbance in a remote control system via a communication network. [Means for solving the problem]

[0007] The remote control system of the present disclosure includes the remote control device of the present disclosure and a controlled object that receives the control data transmitted from the remote control device and operates in accordance with the control data.

[0008] The remote control device of the present disclosure includes: a measurement data receiving unit that receives measurement data measured by a control object from the control object; a metadata receiving unit that receives measurement times of the measurement data of the control object; a processing delay disturbance calculation unit that calculates a processing delay disturbance included in the measurement data received by the measurement data receiving unit based on the measurement time; a communication delay disturbance calculation unit that calculates a communication delay disturbance included in the measurement data received by the measurement data receiving unit; a disturbance compensation unit that compensates for the processing delay disturbance and the communication delay disturbance in the measurement data using the processing delay disturbance and the communication delay disturbance; a control unit that generates control data for controlling the controlled object based on the measurement data compensated for by the disturbance compensation unit; a control data transmission unit that transmits the control data generated by the control unit to the control target; Equipped with.

[0009] The remote control method of the present disclosure includes: a measurement data receiving unit receiving measurement data measured at a control object from the control object; a metadata receiving unit receiving a measurement time of the measurement data of the control target; a processing delay disturbance calculation unit calculates a processing delay disturbance included in the measurement data received by the measurement data receiving unit based on the measurement time; a communication delay disturbance calculation unit that calculates a communication delay disturbance included in the measurement data received by the measurement data receiving unit; a disturbance compensation unit that compensates for the processing delay disturbance and the communication delay disturbance in the measurement data using the processing delay disturbance and the communication delay disturbance; a control unit generating control data for controlling the controlled object based on the measurement data compensated for by the disturbance compensation unit; A control data transmission unit transmits the control data generated by the control unit to the control target.

[0010] The program of the present disclosure is a program for causing a computer to execute each procedure included in the remote control method of the present disclosure.

[0011] The remote control device of the present disclosure may include a control object model unit that estimates the control object without considering a delay time included in the measurement data, and a processing delay model unit that estimates the control object while considering a delay time included in the measurement data. The processing delay disturbance calculation unit may calculate the processing delay disturbance included in the measurement data by comparing the states of the control object obtained by the control object model unit and the processing delay model unit.

[0012] The communication delay disturbance calculation unit may calculate the communication delay disturbance contained in the measurement data by comparing the state of the control object obtained by the processing delay model unit with the measurement data received by the measurement data receiving unit.

[0013] The measurement time may include information about the time when measurement of the measurement data was started in the controlled object.

[0014] The above disclosures can be combined as much as possible. [Effects of the Invention]

[0015] According to the present disclosure, the communication delay disturbance and processing delay disturbance contained in the measurement data are calculated separately and used to compensate for the communication delay disturbance and processing delay disturbance in the measurement data, thereby enabling communication delay disturbance and processing delay disturbance to be separated and disturbance compensation to be made possible in a remote control system via a communication network. [Brief explanation of the drawings]

[0016] [Figure 1] 1 shows an example of the configuration of a remote control system. [Figure 2] 1 shows an example of a functional unit included in a remote control device. [Figure 3] 1 shows an example of a functional unit provided in a control target. [Figure 4] 1 shows an example of a functional unit included in a remote control device. [Figure 5] 1 shows an example of a functional unit provided in a control target. [Figure 6] 1 shows an example of a functional unit included in a remote control device. [Figure 7] 1 illustrates an example embodiment of a remote control method according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0018] (First embodiment) 1 shows an example of the configuration of a remote control system. The remote control system is configured by connecting a remote control device 92 and a controlled object 91 via a communication network 93. The controlled object 91 receives control data transmitted from the remote control device 92 and operates in accordance with the control data.

[0019] The communication network 93 between the remote control device 92 and the control target 91 may be a wired network or a wireless network as long as it is a network that allows information exchange. For example, it is conceivable to use a wireless LAN (Local Area Network) or a mobile communication network such as 5G.

[0020] The remote control device 92 is a digital computer such as a computer (including a server, personal computer, or microcomputer), and has a communication interface. The controlled object 91 can be any system having a sensor and an actuator, but for example, in a mechanical system such as a robot, an electric motor can be used as the actuator and an angle encoder can be used as the sensor. The controlled object 91 is equipped with a communication interface and a digital computer. Below, an example will be explained in which the remote control device 92 controls the angle of a motor provided in the controlled object 91.

[0021] A sensor on the control object 91 side, for example, an encoder in the case of motor angle control, transmits motor angle information as measurement data to a remote control device 92 at regular intervals via a communication network 93. The remote control device 92 transmits an input value to an actuator, for example, a motor, as control data to the control object 91 at regular intervals via the communication network 93 so that the received response signal converges to a target value.

[0022] 2 and 3 show functional block diagrams of a remote control device 92 and a controlled object 93. The remote control device 92 is installed in a location physically separated from the motor, which is the controlled object 91, and the remote control device 92 controls the target angle x cmd is input to the remote control device 92. The remote control device 92 includes a control unit 22, a control data transmission unit 23, and a measurement data reception unit 21.

[0023] The measurement data receiving unit 21 receives the motor angle response x res,r Receive the motor angle response x res,r is affected by the communication delay of the communication network 93, and the motor angle response x res,s The information is delayed by the network delay. Motor angle response x res,r and x res,c are the same value.

[0024] The control unit 22 determines the target angle x cmd and motor angle response x res,c Based on the control data u ref Determine the control data u ref The control data u may be, for example, a reference voltage value or a reference current value for the motor. ref U ref,s The control data u is transmitted to the control target 91. ref and u ref,s are the same value. Here, for the calculation of the control data in the control unit 22, for example, a PID (Proportional-Integral-Derivative) controller can be used as a general-purpose feedback controller.

[0025] The control object 91 includes a driving device 31 that drives at least a part of the control object 91, and a measuring device 32 that measures information on the control object 91. In this embodiment, an example is shown in which the driving device 31 includes a motor driving unit 12 that controls the angle of the motor, and the measuring device 32 includes an angle measuring unit 13 that measures the angle of the motor.

[0026] The driving device 31 includes a control data receiving unit 11 and a motor driving unit 12. The control data receiving unit 11 receives control data u ref,r The motor driver 12 receives the control data u ref,c The motor is driven based on the control data u ref,r and u ref,c are the same value.

[0027] The measurement device 32 includes an angle measurement unit 13 and a measurement data transmission unit 14. The angle measurement unit 13 receives a motor angle x res,p The measurement data transmission unit 14 measures the motor angle response x res,p x res,s The motor angle response x is transmitted to the remote control device 92. res,p and x res,s are the same value.

[0028] Here, on the communication network 93, in addition to transmission delay, communication delay may occur due to buffering delay in the routers and switches that are relayed. ref,r is affected by the communication delay of the communication network 93, and the control data u transmitted from the remote control device 92 ref,s The information is delayed by the network delay compared to the received signal. Furthermore, when measuring a feedback signal in the controlled object 91, a processing delay of the order of 100 milliseconds may occur, especially if image processing or the like is required. For this reason, in the angle measurement unit 13, which requires calculation processing for measurement by an image sensor or the like, a processing delay of the order of 100 milliseconds may occur in the measurement. These communication delays and processing delays are known to have an adverse effect on the stability and performance of a feedback control system.

[0029] Hereinafter, a method for compensating for processing delays and communication delays using CDOB will be described using the example of remote feedback control of a motor. Figure 4 shows an example of the implementation of CDOB in a remote control device 92. CDOB 24 first uses the controlled object model unit 41 to generate a motor angle response model x when there is no communication delay due to the communication network 93 or processing delay due to measurement information processing. m The controlled object model unit 41 may be a linear or nonlinear mathematical model that models the static and dynamic characteristics of the controlled object, or may be a simulation model or an algorithm.

[0030] CDOB24 is a motor angle response model x mand the motor angle response x actually received through communication delays and processing delays res,c The difference between the two is calculated and the filtered output of CDOB is x cmp is the total delay disturbance estimated in the angle dimension from the communication delay on the communication network 93 and the processing delay in the measurement information processing. As for the filtering, for example, if the total delay disturbance exists in the low frequency range, a low pass filter can be used to block noise in the high frequency range and perform disturbance compensation only in the low frequency range.

[0031] The CDOB 24 can cancel out the communication delay disturbance and the processing delay disturbance by collectively estimating the communication delay disturbance caused by the communication network 93 and the processing delay disturbance caused by the measurement information processing and adding it to the motor angle response. Therefore, when designing the remote control device 92, it is possible to reduce the effects of communication delay and processing delay.

[0032] A feature of conventional CDOB is its ability to estimate and compensate for communication delay disturbances and processing delay disturbances all at once without distinguishing between them. However, the causes of communication delays in communication networks93 and processing delays in measurement data processing are not necessarily the same, and the correlation between them cannot be said to be unique. Therefore, if it were possible to distinguish between communication delay disturbances and processing delay disturbances and then perform different filter processing for these disturbances, it would be effective in stabilizing control systems and improving their performance.

[0033] The angle measurement unit 13 measures the motor angle x res While there are methods that are excellent in real-time performance, such as using an optical encoder, IoT (Internet of Things) applications may measure the angle by attaching an external image sensor to an existing motor. Information processing such as image processing may take approximately 100 milliseconds, and it can be considered that there is a processing delay in the angle measurement unit 13. For example, the measurement time is the period from when the position of the motor of the drive device 31 is acquired as an image to when angle information is calculated.

[0034] 5 shows a functional block diagram of the measurement device 32 in the control target 91. The measurement device 32 includes a measurement data transmission unit 14 and a metadata transmission unit 15. The metadata transmission unit 15 receives the measurement time t p Get the metadata p,s t p and t p,s are the same value. As a result, the motor angle response x res,p and measurement time t p is sent.

[0035] Here, the measurement time t p is an arbitrary time that can be grasped as the processing time in the angle measurement unit 13, and can be, for example, the time when the processing starts or the processing time from the start of the processing to the end of the processing. res,s and metadata p,s It is desirable to send the motor angle response x in the same packet. res,s and metadata p,s It is acceptable to send the data in a separate packet as long as an identifier is assigned that clearly identifies the correspondence between the data and the packet.

[0036] 6 shows a functional block diagram of a remote control device 92 according to the present disclosure. The remote control device 92 includes a CDOB 24 and a metadata receiving unit 25. The CDOB 24 includes a controlled object model unit 41, a processing delay model unit 42, a processing delay disturbance calculation unit 44, and a communication delay disturbance calculation unit 45. That is, the remote control device 92 according to the present disclosure includes a measurement data receiving unit 21, a metadata receiving unit 25, a processing delay disturbance calculation unit 44, a communication delay disturbance calculation unit 45, a disturbance compensation unit 26, a control unit 22, and a control data transmission unit 23.

[0037] An embodiment of the remote control method of the present disclosure is shown in Figure 7. In the remote control method of the present disclosure, the remote control device 92 executes steps S11 to S16. In step S11, the measurement data receiving unit 21 receives measurement data measured by the control target 91 from the control target 91. In step S12, the metadata receiving unit 25 receives the measurement time of the measurement data for the control object 91. In step S31, the processing delay disturbance calculation unit 44 calculates the processing delay disturbance included in the measurement data received by the measurement data receiving unit 21 based on the measurement time. In step S13, the communication delay disturbance calculation unit 45 calculates the communication delay disturbance included in the measurement data received by the measurement data receiving unit 21. In step S14, the disturbance compensator 26 compensates for the processing delay disturbance and the communication delay disturbance in the measurement data using the processing delay disturbance and the communication delay disturbance. In step S15, the control unit 22 generates control data for controlling the controlled object 91 based on the measurement data compensated for by the disturbance compensation unit . In step S16, the control data transmitting unit 23 transmits the control data generated by the control unit 22 to the controlled object 91.

[0038] The remote control device 92 of the present disclosure may include a control object model unit 41 and a processing delay model unit 42. In this embodiment, the remote control device 92 calculates a processing delay disturbance using the control object model unit 41, the processing delay model unit 42, and the processing delay disturbance calculation unit 44 in step S13.

[0039] Specifically, the controlled object model unit 41 estimates the controlled object 91 without considering the delay time included in the measurement data. The processing delay model unit 42 estimates the controlled object 91 with consideration of the processing delay time included in the measurement data. The processing delay disturbance calculation unit 44 calculates the processing delay disturbance included in the measurement data by comparing the states of the controlled object 91 obtained by the controlled object model unit 41 and the processing delay model unit 42.

[0040] Furthermore, in step S13, the communication delay disturbance calculation unit 45 calculates the communication delay disturbance contained in the measurement data by comparing the estimated value of the measurement data obtained by the processing delay model unit 42 with the measurement data received by the measurement data receiving unit 21. This makes it possible to calculate the communication delay disturbance from which the processing delay disturbance contained in the measurement data has been excluded. This will be specifically described below with reference to FIG.

[0041] The metadata receiving unit 25 receives the metadata t r Receive and measure time t c is output to the processing delay model unit 42. Measurement time t c is the measurement time t p is the same as

[0042] The controlled object model unit 41 uses the controlled object model to generate a motor angle response model x without communication delay and processing delay. m The processing delay model unit 42 estimates the motor angle response model x when a processing delay is present, using the processing delay controlled object model. m,p The calculation processing in the controlled object model unit 41 and the processing delay model unit 42 can use, for example, a linear or nonlinear mathematical model that models the static characteristics and dynamic characteristics of the controlled object 91, and is not limited to a mathematical model, but may also be a simulation model or an algorithm.

[0043] The processing delay used in the processing delay model unit 42 is the measurement time t c For example, a processing delay in the measuring device 32 on the controlled object 91 side can be exemplified.

[0044] The processing delay model unit 42 generates the motor angle response model x independently of the controlled object model unit 41. m,p However, the data angle response model x obtained by the controlled object model unit 41 may be estimated. m may also be used.

[0045] The processing delay disturbance calculation unit 44 estimates the processing delay disturbance. For example, the processing delay disturbance calculation unit 44 calculates the motor angle response model x m and motor angle response model x m,p The difference between the motor angle response model x and the motor angle response model x is calculated, and then filtered by the first filter processing unit. mis a model that does not include processing delay, and the motor angle response model x m,p is a model including a processing delay. Therefore, the first output x obtained by the processing delay disturbance calculation unit 44 is cmp,p is a processing delay disturbance that estimates the processing delay in the angle dimension.

[0046] The communication delay disturbance calculation unit 45 estimates the communication delay disturbance. For example, the communication delay disturbance calculation unit 45 calculates the motor angle response model x m,p and motor angle response x res,c The difference between the motor angle response model x and the motor angle response model x is calculated, and then filtered by the second filter processing unit. m,p includes processing delay, and the motor angle response x res,c is a value actually received via the communication network 93. Therefore, the second output x obtained by the communication delay disturbance calculation unit 45 cmp,c is a communication delay disturbance that is an estimate of the communication delay on the communication network 93 in the angle dimension.

[0047] The disturbance compensation unit 26 calculates the motor angle response x received by the measurement data receiving unit 21. res,c is compensated for by the disturbance calculated by the CDOB 24. For example, the CDOB 24 compensates for the output x cmp,p and the output x of the communication delay disturbance calculation unit 45 cmp,c The sum of these is calculated and the resulting output is x cmp The disturbance compensation unit 26 outputs the motor angle response x res,c Output to x cmp This gives the motor angle response x res,c The processing delay disturbance and communication delay disturbance are compensated for in the motor angle response x res,c is input to the control unit 22. Therefore, the present disclosure makes it possible to reduce the influence of processing delay disturbance and communication delay disturbance when designing the remote control device 92.

[0048] The first filter processing unit provided in the processing delay disturbance calculation unit 44 and the second filter processing unit provided in the communication delay disturbance calculation unit 45 use a low-pass filter that passes the corresponding low frequency range when the processing delay disturbance or communication delay disturbance exists in the low frequency range, and can block noise in the high frequency range and perform disturbance compensation only in the low frequency range.

[0049] In the present disclosure, the cutoff frequencies of the first filter processing unit and the second filter processing unit can be set to different values ​​depending on the frequency characteristics of the processing delay disturbance and the communication delay disturbance. Also, different types of filters can be used in the first filter processing unit and the second filter processing unit. For example, the first filter processing unit and the second filter processing unit can be arbitrarily selected from frequency filters such as a low-pass filter, a high-pass filter, a band-pass filter, and a band-stop filter.

[0050] (Other embodiments) The remote control device 92 of the present invention can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a communication network. The program of the present disclosure is a program for causing a computer to realize each function of the remote control device 92 according to the present disclosure, and is a program for causing a computer to execute each procedure of the method executed by the remote control device 92 according to the present disclosure. [Explanation of symbols]

[0051] 11: Control data receiver 12: Motor drive unit 13: Angle measurement unit 14: Measurement data transmission unit 15: Metadata sending unit 21: Measurement data receiving unit 22: Control unit 23: Control data transmission unit 24:CDOB 25: Metadata receiver 26: Disturbance compensation section 31: Drive unit 32: Measuring equipment 41: Control object model part 42: Model part with processing delay 44: Processing delay disturbance calculation unit 45: Communication delay disturbance calculation unit 91: Control target 92: Remote control device 93: Communication Network

Claims

1. a measurement data receiving unit that receives measurement data measured by a control object from the control object; a metadata receiving unit that receives measurement times of the measurement data of the control object; a processing delay disturbance calculation unit that calculates a processing delay disturbance included in the measurement data received by the measurement data receiving unit based on the measurement time; a communication delay disturbance calculation unit that calculates a communication delay disturbance included in the measurement data received by the measurement data receiving unit; a disturbance compensation unit that compensates for the processing delay disturbance and the communication delay disturbance in the measurement data using the processing delay disturbance and the communication delay disturbance; a control unit that generates control data for controlling the controlled object based on the measurement data compensated for by the disturbance compensation unit; a control data transmission unit that transmits the control data generated by the control unit to the control target; A remote control device comprising:

2. a control object model unit that estimates the control object without taking into account a delay time included in the measurement data; a processing delay model unit that estimates the control target taking into account a processing delay time included in the measurement data; and Equipped with the processing delay disturbance calculation unit calculates the processing delay disturbance included in the measurement data by comparing the state of the control object obtained by the control object model unit and the state of the control object obtained by the processing delay model unit. The remote control device of claim 1 .

3. the communication delay disturbance calculation unit calculates the communication delay disturbance included in the measurement data by comparing an estimated value of the measurement data obtained by the processing delay model unit with the measurement data received by the measurement data receiving unit. The remote control device according to claim 2 .

4. the measurement time includes information about a time when measurement of the measurement data was started in the control object; The remote control device of claim 1 .

5. A remote control device according to any one of claims 1 to 4; the controlled object that receives the control data transmitted from the remote control device and operates in accordance with the control data; A remote control system comprising:

6. a measurement data receiving unit receiving measurement data measured at a control object from the control object; a metadata receiving unit receiving a measurement time of the measurement data of the control target; a processing delay disturbance calculation unit calculates a processing delay disturbance included in the measurement data received by the measurement data receiving unit based on the measurement time; a communication delay disturbance calculation unit that calculates a communication delay disturbance included in the measurement data received by the measurement data receiving unit; a disturbance compensation unit that compensates for the processing delay disturbance and the communication delay disturbance in the measurement data by using the processing delay disturbance and the communication delay disturbance; a control unit generating control data for controlling the controlled object based on the measurement data compensated for by the disturbance compensation unit; a control data transmission unit that transmits the control data generated by the control unit to the control target; Remote control method.

7. a measurement data receiving unit receiving measurement data measured by a control object from the control object; a step in which a metadata receiving unit receives measurement times of the measurement data in the control object; a step of calculating a processing delay disturbance included in the measurement data received by the measurement data receiving unit based on the measurement time by a processing delay disturbance calculating unit; a step in which a communication delay disturbance calculation unit calculates a communication delay disturbance included in the measurement data received by the measurement data receiving unit; a disturbance compensation unit compensating for the processing delay disturbance and the communication delay disturbance in the measurement data using the processing delay disturbance and the communication delay disturbance; a step in which a control unit generates control data for controlling the controlled object based on the measurement data compensated for by the disturbance compensation unit; a control data transmitting unit transmitting the control data generated by the control unit to the control target; A program that causes a computer to execute the following.

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