JP2007073008A - Positioning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning apparatus that connects a plurality of axes, using a simple connection means and obtains a robust control loop for a system structure where the control loop can be flexibly obtained at the side of the positioning apparatus. <P>SOLUTION: The positioning apparatus has a communication controller 101 which transmits position/speed directions to a plurality of servo drivers 121 to 123 via a single communication interface 111 and receives feedback data from them, and position/speed controllers 102 and 103 which perform position/speed control loop operations based on feedback data received from the communication controller 101, and obtains position control functions by transmitting directions to the servo drivers 121 to 123 that have current control functions. The positioning apparatus is provided with a response history buffer 107 which time-sequentially stores feedback data from the servo drivers 121 to 123, and a direction history buffer 108 which stores histories of speed and current directions that are transmitted to the servo drivers 121 to 123. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a positioning device that controls a servo driver by communication and constructs a control loop.

In a conventional positioning device using communication, a position loop is processed on the servo driver side (see, for example, Patent Document 1).
In some cases, the position loop is processed on the positioning device side (see, for example, Patent Documents 2 and 3).
As described above, the conventional communication positioning device performs processing on the servo driver side in order to construct a control loop, or uses a plurality of communication paths if the position loop is processed on the positioning device side. Yes.
JP 2002-140103 A JP-A-4-900011 JP 2002-354859 A

As described above, in the positioning device based on the conventional communication, when the position control loop is constructed, the position control loop is constructed on the servo driver drive side, or a route different from the command is prepared for transmitting feedback information. There was a need. In the former case, there is a problem that the degree of freedom in constructing a position control loop and a speed control loop is reduced, making it difficult to meet various user requirements. In the latter case, physical connection is complicated. Was a problem.
In addition, since the transmission cycle is generally variable according to the number of slave stations, if a position / speed control loop that should perform processing at a fixed cycle is constructed, a state that is not controllable occurs depending on the number of slave stations. There was a big problem.
The present invention has been made in view of such problems, and constructs a position / speed control loop on the host controller side rather than on the servo driver drive side, and sets the control loop processing cycle to a transmission cycle variable by communication. It is an object of the present invention to provide a positioning device that can actively respond.

In order to solve the above problem, the invention according to claim 1 relates to a positioning device, and provides a communication interface, a position / speed command to a plurality of servo drivers via the communication interface, and the plurality of servos. Positioning that realizes position control function by receiving feedback data from the driver and giving commands to the servo driver that has the current control function via the communication control unit that enables synchronous operation of multiple servo drivers The apparatus includes a buffer for storing feedback data from the servo driver in time series, and a buffer for storing a history of speed commands and current commands commanded to the servo driver.
According to a second aspect of the present invention, there is provided a positioning apparatus, comprising: a communication interface; a position command to a plurality of servo drivers via the communication interface; and a plurality of units receiving feedback data from the plurality of servo drivers. A communication control unit that enables synchronous operation of the servo driver, and a position control unit that performs a position control loop calculation based on feedback data received from the communication control unit, and current control via the communication control unit In a positioning device that realizes a position control function by giving a command to a servo driver having a function,
A response history buffer for storing the feedback data from the servo driver in time series and a command history buffer for storing a history of position commands and current commands commanded to the servo driver are provided.
According to a third aspect of the present invention, in the positioning apparatus according to the first or second aspect, the buffer is a ring buffer.
According to a fourth aspect of the present invention, in the positioning device according to any one of the first to third aspects, the display unit displays each feedback data in the response history buffer and each command in the command history buffer on a screen. An input / output unit for selecting desired data / command from each data / command displayed on the display unit, and the position / speed control unit based on the data / command selected from the input / output unit. It is characterized in that control loop calculation is performed.

According to the first and second aspects of the invention, it is possible to hold a certain number of command values and response data for each transmission cycle of communication, and to determine which command data causes the response data when the control loop is constructed. It becomes possible.
According to the invention of claim 3, since the command value and feedback data for each control cycle are stored in the ring buffer, these are configured as a predetermined number of array data, and the data is stored in order from the top, When data is stored in the last array data, it is possible to return to the top and overwrite the data.
According to the invention described in claim 4, since the correspondence between the command and the feedback data can be left to the user's setting, it is possible to set the communication transmission cycle and the control loop processing cycle to different cycles. It is possible to avoid the beat phenomenon that occurs when the transmission period and the transmission period coincide. This makes it possible to change the control cycle even when the transmission cycle changes due to the communication configuration, and it is possible to construct a stable control system regardless of the system configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of a physical system to which a positioning device according to Embodiment 1 of the present invention is applied.
In the figure, reference numeral 10 denotes a positioning device according to the present invention, which comprises a CPU 100, an input / output unit 104, a display unit 105, a memory 106, a response history buffer 107, a command history buffer 108, and one interface 109. A communication control unit 101, a position control unit 102, and a speed control unit 103 are constructed.
Signals are exchanged from the positioning device 10 to one servo driver 121 of the servo drivers 121 to 123 via the communication path 111. The servo driver 121 and the other servo driver 122, and the servo driver 122 and the other servo driver 123 are connected by only one communication path. Current control units 131 to 133 are built in the servo drivers 121 to 123, respectively, and motors 141 to 143 are connected to the servo drivers 121 to 123, respectively.
As shown in FIG. 1, the present invention is provided with a position control loop and a speed control loop on the positioning device side, and its operation is performed by sending position commands to a plurality of servo drivers via a single communication path 111. Given, feedback data is received from a plurality of servo drivers, and a position control loop and a speed control loop are calculated on the positioning device side.

  The part in which the present invention is different from Patent Document 1 is a part provided with position control and speed control loop processing on the positioning device side. The connection of the driver is a part performed by one communication.

FIG. 2 is a diagram showing a data structure in the positioning device.
107 is a response history buffer for storing feedback data from the servo driver in time series, and 108 is a command history buffer for storing a history of speed commands and current commands commanded to the servo driver. These two history buffers 107 and 108 are ring buffers.

3A and 3B are diagrams for explaining an example of the use of the positioning device according to the present invention provided with such a history buffer. FIG. 3A is a diagram showing the configuration of the positioning device and the shaft, and FIG. 3B is a diagram for each axis. It is a figure which shows the log | history content of a command log | history buffer and a response log | history buffer.
As shown in FIG. 3A, the axes are three axes (# 1 to # 3) here, and these are collectively controlled by the positioning device. As shown in (b), the history contents of the command history buffer and response history buffer for each axis are stored in the command history buffer and response history buffer for each axis # 1 to # 3. ) -Command n-command (n + 2)) and response history (response (n-2) -response n-response (n + 2)) are stored. The buffer group on the arrowhead side (upper side in the figure) of the white arrow shows a normal case, and the buffer group on the arrowhead side (lower side in the figure) of the arrow shows a case of abnormality.
Normally, as in the buffer group on the arrowhead side (upper side in the figure), each buffer stores contents according to a normal order. For example, in the first cycle, the command history buffer of each axis extracts “command (n−2)”, and in the second cycle, the next “command (n−1)” is extracted.

When an operator is operating such a machine, when the operator finds vibration of the axis # 2 of the machine, conventionally, the machine vibration is suppressed by changing the gain or the like. As one of the means that the operator can apply to the machine operation, like gain change, the operator does not use “command (n−2)”, but the axis # as shown under the white arrow in the figure. 2 so that “command (n−3)” is extracted using the command buffer of No. 2. By doing so, it is possible to easily change the control cycle of the axis # 2 by delaying the command by one cycle (corresponding to a delay filter). In the meantime, the other shaft can take out “command (n−2)” as prescribed regardless of the vibration of the shaft # 2.
Similarly, the control cycle can be simply changed by delaying the timing for referring to the response by one cycle.
In any case, according to the present invention, it is possible to change the control for a specific axis without affecting other axes.
As described above, according to the present invention, since the history of command data and response data is stored, it is possible to select a combination of command history n and response history m (n ≠ m). It is possible to realize the construction of a control loop with free settings such as 1) selecting a combination that takes into account the delay of the control system, or (2) selecting a combination that avoids the influence of interference with the communication transmission cycle. It becomes like this.

In the conventional apparatus, the delay of the control system is a fixed period, and this could not be accelerated or delayed, but according to the present invention, in order to compensate for the delay by analyzing the command history and the response history It is possible to cope with how early the command history is shifted.
In the case where the transmission cycle of communication matches the natural frequency of the mechanical system, it has been necessary to change the transmission cycle (generally delay) or apply a notch filter or the like in the conventional apparatus. Notch filters are less effective in the low frequency range, so there is a limit to the application range, and changing the transmission cycle will cause delays for other servo drivers connected to the communication, thus reducing the overall system performance. However, by applying the present invention, it can be dealt with even in a low frequency region, and the transmission cycle of communication is not changed, so that the performance of the entire system is not affected. It is possible to perform compensation only on the target axis.

FIG. 4 is a configuration diagram of a physical system to which the positioning device according to the second embodiment of the present invention is applied.
In the figure, reference numeral 20 denotes a positioning device according to the present invention, which comprises a CPU 200, an input / output unit 104, a display unit 105, a memory 106, a response history buffer 107, a command history buffer 108, and one interface 109. The communication control unit 101 and the position control unit 102 are constructed, and the speed control unit 103 in the CPU 100 in FIG. 1 is moved to the servo drivers 221 to 223 side, which is different from the first embodiment. It is.
Signals are exchanged with one servo driver 221 of the servo drivers 221 to 223 from the positioning device 20 via the communication path 111. The servo driver 221 and the other servo driver 222, and the servo driver 222 and the other servo driver 223 are each connected by only one communication path. Each servo driver 221 to 223 includes a current controller 131 to 133 and the speed controller 211 to 213, respectively, and a motor 141 to 143 is connected to each servo driver 221 to 223.
As shown in FIG. 4, in the second embodiment, a speed control loop is provided on the positioning device side, and its operation is performed by giving position commands to a plurality of servo drivers via a single communication path. Feedback data is received from the servo driver, and the position control loop is calculated on the positioning device side.

  According to the second embodiment, by constructing the speed control unit on the servo driver side, there is an advantage that the load on the positioning side is reduced compared to the first embodiment. Conversely, the software load on the servo driver side is reduced. There are also disadvantages that it becomes large and various corrections relating to speed control cannot be implemented on the positioning side.

As described above, according to the present invention, the history of command data and response data is managed, and the transmission period determined by the configuration of the communication system by freely selecting the combination of commands and responses to be applied to the control loop. It is possible to provide a control loop that is not interfered by.
As a result, a complicated control theory can be realized on the positioning device side while being simple connection means, so that a multi-axis system can be constructed at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is the positioning apparatus and system block diagram which show 1st Example of this invention. It is a data block diagram of a positioning device. It is a figure explaining one example of use of the positioning device concerning the present invention. It is a positioning device and system configuration diagram showing a second embodiment of the present invention.

Explanation of symbols

10. Positioning device according to Embodiment 1 of the present invention 20 Positioning device 100, 200 CPU according to Embodiment 2 of the present invention
104 I / O unit 105 Display unit 106 Memory 107 Response history buffer 108 Command history buffer 109 Interface 101 Communication control unit 102 Position control unit 103, 231 to 233 Speed control unit 111 Communication path 121 to 123, 221 to 223 Servo driver 131 ~ 133 Current control part 141 ~ 143 Motor

Claims (4)

One communication interface and communication that gives position / speed commands to a plurality of servo drivers via the communication interface and receives feedback data from the plurality of servo drivers to enable the synchronization operation of the plurality of servo drivers. A control unit and a position / speed control unit that performs a position / speed control loop calculation based on feedback data received from the communication control unit, and commands a servo driver having a current control function via the communication control unit. In the positioning device that realizes the position control function by giving
A positioning apparatus comprising: a response history buffer for storing the feedback data from the servo driver in time series; and a command history buffer for storing a history of speed commands and current commands commanded to the servo driver. One communication interface, and a communication control unit that provides position commands to a plurality of servo drivers via the communication interface and receives feedback data from the plurality of servo drivers, thereby enabling a synchronous operation of the plurality of servo drivers. And a position control unit that performs a position control loop calculation based on feedback data received from the communication control unit, and gives position control to the servo driver having a current control function via the communication control unit. In the positioning device that realizes the function,
A positioning apparatus comprising: a response history buffer for storing the feedback data from the servo driver in time series; and a command history buffer for storing a history of position commands and current commands commanded to the servo driver.   The positioning device according to claim 1, wherein the two history buffers are ring buffers.   A display unit for displaying each feedback data in the response history buffer and each command in the command history buffer on a screen, and an input / output unit for selecting desired data / command from each data / command displayed on the display unit 3. The positioning apparatus according to claim 1, wherein the position / speed control unit performs a position / speed control loop calculation based on the data / command selected from the input / output unit.

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