Linear motor system

Abstract

The linear motor system has fixed parts (11, 12), movable parts (3), and control devices (21, 22) that energize the fixed parts (11, 12). The control device (21) calculates the current command value towards the fixed part (11) based on a first speed integral value obtained by integrating the speed deviation between the speed command towards the movable part (3) and the actual speed of the movable part (3), and performs a first digital filter operation for the current command value. The control device (22) calculates the current command value towards the fixed part (12) based on a second speed integral value obtained by integrating the speed deviation between the speed command towards the movable part (3) and the actual speed of the movable part (3), and performs a second digital filter operation for the current command value. The current command calculation unit (222) calculates the second speed integral value based on the first speed integral value used by the control device (21), and performs a second digital filter operation using the internal value in the first digital filter operation performed by the control device (21).

Description

Technical Field

[0001] The present invention relates to a linear motor system using a plurality of fixed members and movable members arranged opposite to the fixed members. Background Technology

[0002] A linear motor system exists, comprising: a fixed member having multiple armature winding units; a movable member having a permanent magnet disposed opposite to the fixed member; and a control device for controlling the energization of the fixed member. The control device of this linear motor system sequentially switches the energization of the fixed member in accordance with the position of the movable member, thereby generating thrust. In this linear motor system, to reduce the impact caused by the speed change of the movable member during the switching of energization towards the fixed member, i.e., switching impact, it is preferable to ensure that the current values ​​energized to adjacent fixed members are continuous.

[0003] The control device for the linear motor system described in Patent Document 1 has a power-on switching compensation function, that is, it performs switching compensation for the armature winding unit of the switching target when switching the energized object. This power-on switching compensation function involves the exchange of speed integral values ​​between control devices, obtained by continuously adding the difference between the speed command value and the current speed. The control device for the linear motor system described in Patent Document 1 uses the received speed integral value to control the energized object, thereby reducing switching shocks.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2015-33240 Summary of the Invention

[0005] However, in the technology of the aforementioned Patent Document 1, the data transmitted and received between control devices through the power-on switching compensation function is limited to the speed integral value, thus resulting in insufficient reduction of switching shock.

[0006] The present invention was made in view of the above circumstances, and its object is to provide a linear motor system that can sufficiently reduce the switching shock that occurs when switching is performed by energizing the opposing fixed member.

[0007] To solve the aforementioned problems and achieve the objective, the linear motor system of the present invention includes: a first fixed member; a second fixed member; and a movable member disposed opposite to the first fixed member and the second fixed member. Furthermore, the linear motor system of the present invention includes: a first control device that, when the movable member is opposite to the first fixed member, executes energization of the first fixed member based on a first speed command or a first position command to the movable member, thereby driving the movable member; and a second control device that, when the movable member is opposite to the second fixed member, executes energization of the second fixed member based on a second speed command or a second position command to the movable member, thereby driving the movable member. Furthermore, the linear motor system of the present invention includes an instruction creation unit that, when the movable member moves from the first fixed member to the second fixed member, sends a first speed instruction or a first position instruction to the first control device, and sends a second speed instruction or a second position instruction to the second control device, thereby sequentially executing the energization of the first fixed member by the first control device and the energization of the second fixed member by the second control device. The first control device includes: a first current instruction calculation unit that calculates a first current instruction value for the first fixed member based on a first speed integral value obtained by integrating the speed deviation between the first speed instruction and the actual speed of the movable member, i.e., the current speed; and a first digital filter that performs a first digital filter operation for the first current instruction value. The second control device includes: a second current command calculation unit that calculates a second current command value for the second fixed member based on a second speed integral value obtained by integrating the speed deviation between the second speed command and the actual speed of the movable member, i.e., the current speed; a second digital filter that performs a second digital filter operation for the second current command value; and a control quantity acquisition unit that acquires from the first control device the first speed integral value used by the first current command calculation unit and the internal values ​​in the first digital filter when the first digital filter performs the first digital filter operation. The second current command calculation unit calculates the second speed integral value based on the first speed integral value, and the second digital filter performs the second digital filter operation using the internal values.

[0008] The effects of the invention

[0009] The linear motor system of the present invention has the following effect: it can significantly reduce the switching shock that occurs when switching is performed by energizing the opposing fixed member. Attached Figure Description

[0010] Figure 1 This is a diagram showing the structure of the linear motor system involved in the implementation method.

[0011] Figure 2 This is a diagram illustrating a structural example of the control device included in the linear motor system according to the embodiment.

[0012] Figure 3 This is a diagram illustrating a structural example of the delay compensation unit included in the control device according to the embodiment.

[0013] Figure 4 This diagram illustrates the delay compensation process performed by the digital filter and delay compensation unit of the control device according to the embodiment.

[0014] Figure 5 This is a diagram illustrating an example of the hardware structure of the control device involved in implementing the embodiment. Detailed Implementation

[0015] The linear motor system according to the embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0016] Implementation method.

[0017] Figure 1 This is a diagram showing the structure of the linear motor system according to the embodiment. The linear motor system 10 includes a fixed component group 1, a control device group 2, a movable component 3, an encoder reader head 4, a reading unit group 5, a position information communication line 6, a control information communication line 7, an instruction creation unit 8, and a guide unit 9, realizing a servo mechanism.

[0018] The fixing assembly 1 has multiple fixing members 11 to 14. Each fixing member 11 to 14 has its own assembly of windings, namely an armature winding unit. Furthermore, the number of fixing members included in the fixing assembly 1 can be greater than or equal to 5, or 3 or 2. The fixing members 11 to 14 generate thrust by energizing the control device assembly 2.

[0019] Control device group 2 has multiple control devices 21 to 24. Control device 21 controls the fastener 11, control device 22 controls the fastener 12, control device 23 controls the fastener 13, and control device 24 controls the fastener 14. As described above, control device group 2 has the same number of control devices 21 to 24 as fastener group 1 has fasteners 11 to 14.

[0020] Control devices 21-24 are each connected to the armature winding units of the fixed members 11-14 and perform energization control on the armature winding units. Control devices 21-24 designate the armature winding unit opposite to the movable member 3 among the armature winding units of the fixed members 11-14 as the energized object. Control devices 21-24 perform energization control calculations based on speed commands for each energized object, and based on the calculation results, sequentially energize the armature winding units of the energized object, thereby driving the movable member 3.

[0021] Control devices 21-24 perform power-on control according to the position command output from the command creation unit 8. Alternatively, control devices 21-24 can also perform power-on control according to the speed command output from the command creation unit 8. Control devices 21-24 execute a control loop based on the position command to the fixing members 11-14, thereby performing power-on control to the fixing members 11-14.

[0022] The movable member 3 has a permanent magnet and moves on the guide section 9 by the thrust generated by the fixed members 11 to 14. An encoder read head 4 is mounted on the movable member 3. The encoder read head 4 outputs light, magnetic force, etc. to the reading section assembly 5.

[0023] The reading unit group 5 has the same number of encoder reading units 51 to 54 as the fixing members 11 to 14 in the fixing member group 1. Here, the reading unit group 5 has four encoder reading units 51 to 54. The encoder reading units 51 to 54 are arranged at constant intervals opposite to the encoder reading head 4. The encoder reading units 51 to 54 are arranged along the guide 9, and the movable member 3, on which the encoder reading head 4 is mounted, moves between the encoder reading units 51 to 54 and the guide 9.

[0024] Encoder reading units 51-54 have a transparent scale, which detects light, magnetic force, etc., that pass through the scale, thereby detecting the position of the encoder reading head 4. The encoder reading units 51-54 can detect the position of the encoder reading head 4 when the relative area between them and the encoder reading head 4 is greater than or equal to a predetermined amount. The mounting interval of the encoder reading units 51-54 is, for example, a constant interval. However, the mounting interval of the encoder reading units 51-54 is not limited to a constant interval and can be other intervals. Furthermore, in this embodiment, the relative area between the encoder reading units 51-54 and the encoder reading head 4 that allows for position detection is assumed to be greater than or equal to 50% of the area of ​​the encoder reading head 4. That is, any one of the encoder reading units 51-54 can be used for position detection during the movement of the movable member 3.

[0025] If the encoder reading units 51 to 54 detect the position of the encoder reading head 4, they will send the position information indicating the detected position to the control devices 21 to 24 and the instruction creation unit 8 via the position information communication line 6 and the control information communication line 7.

[0026] The control information communication line 7 is a communication bus used for transmitting and receiving information, and is connected to the control devices 21-24, the position information communication line 6, and the command creation unit 8. The position information communication line 6 is a communication bus used for transmitting and receiving information, and is connected to the encoder reading units 51-54 and the control information communication line 7.

[0027] The command creation unit 8 sends position commands to the control devices 21-24 via the control information communication line 7. Additionally, the command creation unit 8 sends the current ratio Mag (described later) to the control devices 21-24 via the control information communication line 7. The command creation unit 8 generates position commands based on the position information sent by the reading unit group 5 via the position information communication line 6 and the control information communication line 7.

[0028] Furthermore, it can replace the position information communication line 6 and the control information communication line 7, and perform communication between the encoder reading units 51-54 and the control devices 21-24 via an information processing device. The information output from the encoder reading units 51-54 can be directly imported into the control devices 21-24. In addition, the communication between the encoder reading units 51-54 and the control devices 21-24 can be performed via the instruction creation unit 8.

[0029] Based on the position information of the movable member 3, the command creation unit 8 determines which of the fixed members 11 to 14 is opposite to the movable member 3, and outputs a power-on command for power-on control to the control device connected to the fixed member opposite to the movable member 3. The control devices 21 to 24 energize the fixed members 11 to 14 according to the power-on command from the command creation unit 8, thereby generating thrust and driving the movable member 3. In this case, the command creation unit 8 outputs the power-on command to the adjacent control device, i.e., the downstream control device, just before the movable member 3 is about to come into contact with the adjacent fixed member, thereby enabling continuous generation of thrust between the fixed members.

[0030] When switching the power-on control process as described above, a switching shock may sometimes occur due to a change in the speed of the movable element 3. Therefore, the linear motor system 10 of this embodiment has a digital filter for suppressing mechanical resonance and performs delay compensation to ensure the continuity of the filter output value, thereby suppressing switching shocks. In addition, the linear motor system 10 performs delay compensation for information obtained from the adjacent control device, i.e., the control device on the front stage, thereby suppressing switching shocks.

[0031] In this embodiment, the fixing member 11 is positioned on the right side, and the fixing member 12 is positioned on the left side. That is, in the linear motor system 10, the fixing member 11 is positioned at the rightmost end, the fixing member 12 is the second one from the right, the fixing member 13 is the third one from the right, and the fixing member 14 is positioned at the leftmost end. In this case, in the linear motor system 10, the movable member 3 moves from the right side to the left side. That is, the movable member 3 moves from the fixing member 11 to the fixing member 12, from the fixing member 12 to the fixing member 13, and from the fixing member 13 to the fixing member 14.

[0032] Of the fixing members 11 to 14, the one positioned on the rear side of the movable member 3 in the direction of movement, compared to the first fixing member, is the second fixing member. Therefore, when fixing member 11 is the first fixing member, fixing member 12 is the second fixing member. When fixing member 12 is the first fixing member, fixing member 13 is the second fixing member. When fixing member 13 is the first fixing member, fixing member 14 is the second fixing member.

[0033] Furthermore, when control device 21 is the first control device, control device 22 is the second control device. When control device 22 is the first control device, control device 23 is the second control device. When control device 23 is the first control device, control device 24 is the second control device.

[0034] When control device 21 is the first control device and control device 22 is the second control device, the speed command used by control device 21 is the first speed command, and the speed command used by control device 22 is the second speed command. In this case, the position command used by control device 21 is the first position command, and the position command used by control device 22 is the second position command.

[0035] In the following description, the case where control device 21 is the first control device and control device 22 is the second control device will be explained.

[0036] Here, specific structural examples of the control devices 21 to 24 included in the linear motor system 10 according to the embodiment will be described. Figure 2 This diagram illustrates a structural example of the control device included in the linear motor system according to the embodiment. Furthermore, since control devices 21 to 24 have the same structure, the structures of two adjacent control devices, namely control devices 21 and 22, will be described here. Additionally, the structure of the instruction creation unit 8 will be described.

[0037] Control device 21 includes a speed command calculation unit 211, a current command calculation unit 212, a digital filter 213 (such as a low-pass filter), a current control unit 214, an arithmetic unit 216, subtraction units 210 and 219, and a multiplication unit 215. Control device 22 includes a speed command calculation unit 221, a current command calculation unit 222, a digital filter 223, a current control unit 224, an arithmetic unit 226, subtraction units 220 and 229, and a multiplication unit 225. The current command calculation unit 212 is a first current command calculation unit, and the current command calculation unit 222 is a second current command calculation unit.

[0038] Furthermore, control devices 21 and 22 each have a control quantity acquisition unit 227 and a delay compensation unit 228. Additionally, in Figure 2The control quantity acquisition unit 227 and delay compensation unit 228 of the control device 21 are omitted from the illustration. The instruction creation unit 8 includes a current ratio creation unit 81 and a position instruction creation unit 82.

[0039] The connection structure of the structural elements of control device 21 is the same as that of control device 22; therefore, the connection structure of the structural elements of control device 22 will be described. Subtraction unit 220 is connected to position information communication line 6, control information communication line 7, and speed command calculation unit 221. Speed ​​command calculation unit 221 and arithmetic unit 226 are connected to subtraction unit 229. Furthermore, arithmetic unit 226 is connected to position information communication line 6 and current control unit 224. Subtraction unit 229 is connected to current command calculation unit 222. Current command calculation unit 222 is connected to digital filter 223 and control information communication line 7. Digital filter 223 is connected to current control unit 224 and control information communication line 7. Current control unit 224 is connected to multiplication unit 225. Multiplication unit 225 is connected to fixing member 12 and control information communication line 7.

[0040] Furthermore, the control quantity acquisition unit 227 is connected to the current command calculation unit 222, the digital filter 223, and the control information communication line 7. Additionally, the delay compensation unit 228 is connected to the current ratio creation unit 81, the current command calculation unit 222, and the digital filter 223. The current ratio creation unit 81 is connected to the position information communication line 6 and the control information communication line 7, and the position command creation unit 82 is connected to the control information communication line 7.

[0041] The current ratio creation unit 81 receives the position information of the encoder read head 4 sent by the encoder read units 51 and 52 via the position information communication line 6. Furthermore, the current ratio creation unit 81 creates a current ratio Mag based on the position information. This current ratio Mag represents the ratio of the current used for power-on control when switching the power-on control device. The current ratio Mag is the ratio of the current value during power-on control switching to the normal current value. Here, the current ratio creation unit 81 creates the current ratio Mag for control device 21 and the current ratio Mag for control device 22 when switching the power-on control device from control device 21 to control device 22. The current ratio creation unit 81 sends the current ratio Mag to the multiplication units 215 and 225 via the control information communication line 7.

[0042] The position command creation unit 82 creates a position command Pcmd that specifies the position of the movable part 3. The position command creation unit 82 sends the position command Pcmd to the subtraction units 210 and 220 via the control information communication line 7.

[0043] The subtraction unit 220 of the control device 21 calculates the difference between the command input value, i.e., the position command Pcmd, and the current position Pos, i.e., the position difference value. The position command Pcmd is a command indicating the desired position of the movable member 3, and the current position Pos is the actual position of the movable member 3. The current position Pos is detected by the encoder reading units 51 and 52.

[0044] The speed command calculation unit 211 calculates the speed command value Vcmd based on the position difference value. The speed command value Vcmd represents the command for the desired speed of the movable member 3. The speed command calculation unit 211 calculates the speed command value Vcmd that makes the position difference value 0, that is, makes the position command Pcmd the same as the current position Pos. The speed command value Vcmd is the command used to control the position of the movable member 3 to a position where the difference between the position command Pcmd and the current position Pos disappears. As described above, the speed command calculation unit 211 calculates the speed command value Vcmd based on the position difference value. The speed command calculation unit 211 outputs the speed command value Vcmd to the subtraction unit 219.

[0045] The arithmetic unit 216 takes the current position Pos as input and performs velocity calculations to calculate the current velocity Velo. The current velocity Velo is the actual velocity of the movable member 3. The arithmetic unit 216 converts the current position Pos into velocity through differential operations, etc., and calculates the velocity of the movable member 3, i.e., the current velocity Velo. The arithmetic unit 216 outputs the current velocity Velo to the subtraction unit 219.

[0046] Furthermore, the arithmetic unit 216 performs magnetic pole calculations using the current position Pos as input, thereby calculating the current magnetic pole Theta. The current magnetic pole Theta is the actual magnetic pole of the movable member 3. The current magnetic pole Theta is the magnetic pole used for magnetic pole control. The arithmetic unit 216 calculates the current magnetic pole Theta based on the current position Pos, which represents the position of the magnetic pole from the reference position when the position of the N pole of the permanent magnet of the movable member 3 is relative to the center position of the armature winding of the fixed member 11 is set as the reference position.

[0047] The subtraction unit 219 calculates the difference between the speed command value Vcmd and the current speed Velo, i.e., the speed deviation (hereinafter referred to as the speed difference Vdif), and inputs it to the current command calculation unit 212. The current command calculation unit 212 calculates the current command value based on the speed difference Vdif. The current command calculation unit 212 calculates a current command value that makes the speed difference Vdif zero, that is, that makes the speed command value Vcmd and the current speed Velo the same. The current command value is a command used to control the speed of the movable member 3 to a speed at which the difference between the speed command value Vcmd and the current speed Velo disappears. As described above, the current command calculation unit 212 calculates the current command value based on the speed difference Vdif.

[0048] The current command value calculated by control device 21 is the first current command value, and the current command value calculated by control device 22 is the second current command value. The current command calculation unit 212 outputs the calculated current command value to the digital filter 213.

[0049] Digital filter 213 performs digital filter calculations on the output value from current command calculation unit 212, i.e., the current command value, and outputs it to current control unit 214. Current control unit 214 calculates the current command value after magnetic pole adjustment based on the output value from digital filter 213 and the current magnetic pole Theta from calculation unit 216. Current control unit 214 outputs the calculated current command value to multiplication unit 215.

[0050] The multiplication unit 215 multiplies the current ratio Mag sent from the current ratio creation unit 81 with the current command value calculated by the current control unit 214, and applies the multiplication result, i.e., the current value, to the fixing member 11. Furthermore, these processes performed by the control device 21 are performed identically in the control device 22, and therefore their description is omitted.

[0051] The control of the movable member 3 described above applies when there is only one fixed member energizing the movable member 3. When the movable member 3 spans two fixed members, i.e., when there are two fixed members energizing the movable member 3, the linear motor system 10 needs to perform the aforementioned calculations and energize both fixed members. For example, when the movable member 3 is facing both fixed members 11 and 12, control devices 21 and 22 perform the calculations and energize the movable member 3.

[0052] In the linear motor system 10, the power-on process can be shifted in different ways, such as power-on via control device 21 only, power-on via both control device 21 and control device 22, or power-on via control device 22 only. Alternatively, the linear motor system 10 may switch to power-on via control device 22 only after power-on via control device 21, without powering on via both control device 21 and control device 22.

[0053] Furthermore, in the case of a linear motor system 10 having multiple movable parts 3, the number of movable parts 3 that each control device 21-24 can process is limited, depending on the processor capabilities, memory capacity, etc., of the control devices 21-24 included in the system environment of the linear motor system 10. Therefore, the control devices 21-24 need to perform calculations after determining the status of each movable part 3. Therefore, the control devices 21-24 do not perform calculations continuously, but rather begin calculations from a specific moment before power-on.

[0054] For example, when switching from a de-energized state to an energized state, the current supplied to the control device 22 must be continuous with the current supplied through the control device 21 until the very last moment. Discontinuity would cause switching shocks in the movable member 3. Therefore, in this embodiment, to maintain the continuity of the current, the control quantity acquisition unit 227 of the control device 22 acquires internal control quantities from the control device 21 that depend on calculations performed before the start of energization, before switching to the energized state. The control quantity acquisition unit 227 sets the acquired internal control quantities in the control device 22.

[0055] Specifically, the current command calculation unit 212 of the control device 21 calculates one of the internal control quantities, namely the speed integral value Intg, and sends the calculated speed integral value Intg to the control quantity acquisition unit 227 of the control device 22 via the control information communication line 7. The current command calculation unit 212 continuously adds the difference between the speed command value Vcmd and the current speed Velo, namely the speed deviation, thereby calculating the speed integral value Intg.

[0056] Furthermore, the digital filter 213 of the control device 21 performs digital filter operations using one of its internal control quantities, namely the filter control quantity Filt. The digital filter 213 transmits the filter control quantity Filt to the control quantity acquisition unit 227 of the control device 22 via the control information communication line 7. The filter control quantity Filt is an internal value of the digital filter 213 used in the digital filter operations.

[0057] The control quantity acquisition unit 227 of the control device 22 acquires the speed integral value Intg and the filter control quantity Filt from the control device 21 and sets them in the control device 22 itself. In this case, a communication delay is assumed in the communication processing using the control information communication line 7. In this case, when the internal control quantity sent by the control device 21 is transmitted to the control device 22, it becomes an internal control quantity that includes a delay time equivalent to the communication delay. If the control device 22 directly uses the internal control quantity, the speed integral value Intg and the filter control quantity Filt acquired by the control quantity acquisition unit 227 from the control device 21 are processed in the control device 22 as speed integral values ​​Intg' and filter control quantities Filt' that include the delay time, respectively. As described above, relative to the latest speed integral value used by the control device 21, the speed integral value acquired by the control device 22 becomes a speed integral value Intg' that includes the delay.

[0058] In this situation, the continuity of the current flow corresponding to the delay time is impaired in the linear motor system 10, resulting in compromised controllability. Furthermore, in the digital filter 223 of the control device 22, the filter control quantity becomes discontinuous, thus sometimes failing to achieve the desired vibration suppression effect. Therefore, in this embodiment, a delay compensation unit 228 for compensating for communication delay time is provided in the control devices 21-24.

[0059] The delay compensation unit 228 compensates for the delay time, thereby calculating the speed integral value (hereinafter referred to as the speed integral value Intg") without delay time from the speed integral value Intg'. The delay compensation unit 228 obtains the speed difference value, i.e., the speed difference Vdif, between the speed command value Vcmd and the current speed Velo from the subtraction unit 229, and sends the speed integral value Intg" calculated using the speed difference Vdif to the current command calculation unit 222.

[0060] Furthermore, the delay compensation unit 228 sends the number of digital filter operations, i.e., the number of digital filter operations, to the digital filter 223. The number of digital filter operations corresponds to the communication delay time. Additionally, the delay compensation unit 228 receives a notification from the digital filter 223 indicating that an output value with no delay time has been obtained.

[0061] In the linear motor system 10, the control device 22 sends the speed integral value Intg and the filter control quantity Filt of the control device 22 to the control device 23 through the same processing as the control device 21. Furthermore, the control device 23 controls the movable member 3 through the same processing as the control device 22.

[0062] Similarly, in the linear motor system 10, the control device 23 sends its speed integral value Intg and filter control quantity Filt to the control device 24 through the same processing as the control device 21. Furthermore, the control device 24 controls the movable element 3 through the same processing as the control device 22.

[0063] Here, the structure of the delay compensation unit 228 will be explained. Figure 3 This diagram illustrates a structural example of the delay compensation unit included in the control device according to the embodiment. The delay compensation units 228 included in control devices 21 to 24 have the same structure; therefore, the structure of the delay compensation unit 228 included in control device 22 will be described here. The delay compensation unit 228 is connected to the current command calculation unit 222 and the digital filter 223, but... Figure 3 The diagram showing the connection between the digital filter 223 and the filter is omitted.

[0064] Furthermore, in the following description, the same position command Pcmd and the current position Pos are input to the control device 21 and control device 22 from the stage before full operation.

[0065] The subtraction unit 229 calculates the difference between the speed command value Vcmd and the current speed Velo, and outputs it as the speed difference Vdif to the current command calculation unit 222 and the delay compensation unit 228. The delay compensation unit 228 includes a delay time determination unit 235, a switch 231, a multiplication unit 232, an addition unit 233, and an integration unit 234.

[0066] In order to eliminate the delay in the speed integral value Intg' from the control device 21 to the control device 22, the delay time determination unit 235 determines whether integration processing via speed difference Vdif can be performed based on the delay time. For example, the delay time determination unit 235 takes the timing of the control device 22 receiving the speed integral value Intg' as the starting point and outputs a disconnect command to the switch 231 at a timing earlier than the backtracking delay time.

[0067] As described above, the delay time determination unit 235 determines the delay time of communication between control devices 21 and 22, and controls switch 231 based on the delay time. For example, the delay time determination unit 235 outputs an on or off command to switch 231 according to an on or off instruction sent by instruction creation unit 8 via control information communication line 7. That is, the delay time determination unit 235 determines, based on the on or off instruction sent from instruction creation unit 8, whether the delay time of communication between control devices 21 and 22 is the time it takes for switch 231 to output an on command or the time it takes for switch 231 to output an off command.

[0068] If the delay time determination unit 235 receives an on instruction from the instruction creation unit 8, it outputs an on instruction to the switch 231; if it receives an off instruction from the instruction creation unit 8, it outputs an off instruction to the switch 231. According to the instruction from the delay time determination unit 235, the switch 231 switches its output to the multiplication unit 232 to either "0" or the speed difference Vdif.

[0069] For example, if switch 231 receives a disconnect command from delay time determination unit 235, it switches its output to "0". As a result, switch 231 outputs "0" to multiplication unit 232, and therefore no integration processing is performed for the speed difference Vdif.

[0070] Then, the delay time determination unit 235 outputs an activation command to the switch 231 at a timing that is the same as or less than the delay time. As a result, the switch 231 switches its output to the speed difference Vdif. Consequently, the speed difference Vdif is output from the switch 231. This speed difference Vdif is sent to the multiplication unit 232. The multiplication unit 232 multiplies the speed difference Vdif by the integration gain Ki, thereby calculating the multiplication value Intgd, and outputs the multiplication value Intgd to the addition unit 233. The addition unit 233 sends the speed integral value Intg' and the multiplication value Intgd to the integration unit 234.

[0071] The integrator 234 sequentially accumulates the multiplication value Intgd relative to the speed integral value Intg', thereby performing integration processing through the multiplication value Intgd. Therefore, the delay compensation unit 228 calculates the speed integral value Intg" excluding the delay time by adding the sum of the integrals that should be accumulated over the delay time (i.e., the multiplication value Intgd) to the integrals including the delay time (i.e., the speed integral value Intg'). Furthermore, the integrator 234 only performs the addition of the speed integral value Intg' once; after the addition of Intg', it does not add it again until the speed integral value Intg' is set again. The speed integral value Intg is the first speed integral value, and the speed integral value Intg" is the second speed integral value.

[0072] As described above, the speed integral value Intg' obtained by the control quantity acquisition unit 227 from the control device 21 contains a delay. Therefore, if the speed integral value Intg' is directly added to the speed difference Vdif, the resulting speed integral value contains a delay.

[0073] In this embodiment, the delay compensation unit 228 adds the speed integral value Intg” (excluding the delay time) obtained by adding the sum of the multiplication values ​​Intgd that should be accumulated during the delay time to the speed integral value Intg’ including the delay time, and the speed difference Vdif.

[0074] The delay compensation unit 228 calculates the speed integral value Intg” using, for example, a circular buffer. In this case, the delay compensation unit 228 uses a circular buffer capable of storing all speed differences Vdif corresponding to the delay time. The delay compensation unit 228 uses, for example, a circular buffer where speed differences Vdif older than the delay time are continuously overwritten by speed differences Vdif within the delay time. Thus, the delay compensation unit 228 always stores the number of speed differences Vdif that can be stored in the circular buffer, that is, the speed differences Vdif within the same time as the delay time. Thus, in the circular buffer, speed differences Vdif of the delay time amount are always stored, and speed differences Vdif older than the delay time are deleted. When the delay compensation unit 228 receives the speed integral value Intg’, it adds all the speed differences Vdif of the delay time amount accumulated in the circular buffer to the speed integral value Intg’, thereby calculating the speed integral value Intg”.

[0075] The current command calculation unit 222 adds the speed integral value Intg” calculated by the delay compensation unit 228 to the speed difference Vdif. The multiplication unit 236 multiplies the sum by the speed proportional gain Kp, and outputs the multiplication result as the input value x[n] to the digital filter 223. The speed proportional gain Kp is a gain used to adjust the tracking performance of the speed loop. The input value x[n] is the current command, which is sent to the digital filter 223.

[0076] Next, the specific processing of the delay compensation unit 228 on the digital filter 223 will be explained. Figure 4 This diagram illustrates the delay compensation process performed by the digital filter and delay compensation unit of the control device according to the embodiment. Here, an example of the digital filter 223 is described as a first-order IIR (Infinite Impulse Response) notch filter.

[0077] Digital filter 223 adds the value obtained by multiplying the current input value (x[n]) by the filter coefficient a0, the value obtained by multiplying the previous input value (x[n-1]) by the filter coefficient a1, and the value obtained by multiplying the input value two years ago (x[n-2]) by the filter coefficient a2. Digital filter 223 then outputs the current output value (y[n]) as the sum of these summed values.

[0078] As described above, when constructing the digital filter 223, it is necessary to compare the values ​​two times before the start of the operation. Specifically, the previous input value x[n-1], the previous input value x[n-2], the previous output value y[n-1], and the previous output value y[n-2] are required. The control device 22 can obtain these four values ​​from the control device 21 through the control quantity acquisition unit 227. In this embodiment, these four values, including them, are represented as the filter control quantity Filt, and the filter control quantity including the delay time is represented as the filter control quantity Filt'.

[0079] Furthermore, the filter control quantity Filt may or may not include the current input value x[n]. When the filter control quantity Filt does not include the current input value x[n], the delay compensation unit 228 of the control device 22 calculates the current input value x[n] using the speed difference Vdif. Alternatively, the digital filter 223 may also calculate the current input value x[n] using the speed difference Vdif. The method for calculating the current input value x[n] will be described later.

[0080] Digital filter 223 repeats the digital filter operation multiple times, according to the number of digital filter operations specified by delay compensation unit 228. Figure 4 In this diagram, the processing of a single-order digital filter operation is illustrated as a digital filter function block. That is, the number of digital filter function blocks corresponds to the number of digital filter operations.

[0081] If the number of digital filter operations equivalent to the delay time performed by the control quantity acquisition unit 227 is set to A, then the internal values ​​of the digital filter 223 that are traced back from the moment the filter control quantity Filt' is acquired become the current input value x[n-A], the previous input value x[n-1-A], the input value two years ago x[n-2-A], the current output value y[n-A], the previous output value y[n-1-A], and the output value two years ago y[n-2-A]. The method for restoring the internal values ​​of the digital filter 223 before these A operations to the values ​​equivalent to the current value will be explained.

[0082] First, the delay time determination unit 235 obtains the value of the number of digital filter operations A corresponding to the delay time. An example of this method is that the delay time determination unit 235 uses information obtained from the instruction creation unit 8 via the control information communication line 7. In this case, the instruction creation unit 8 calculates the value of the number of digital filter operations A based on the relationship between the processing cycle of the digital filter operation and the communication delay time. For example, if the processing cycle of the digital filter operation is 50 μs and the communication delay time is 200 μs, four digital filter operations are performed within the communication delay period. Therefore, in this case, the instruction creation unit 8 notifies the delay time determination unit 235 of the number of four digital filter operations A.

[0083] Furthermore, the value of the number of operations A of the digital filter can be obtained by pre-setting parameters for the control device 22, or by directly setting it through software programming, etc.

[0084] The control device 22 performs one digital filter operation through the digital filter 223, thereby obtaining the value of the current output value y[n-A].

[0085] Next, when the control device 22 performs the operation through the digital filter 223 again, the internal values ​​of the digital filter 223 become the current input value x[n+1-A], the previous input value x[n-A], the input value before that x[n-1-A], the current output value y[n+1-A], the previous output value y[n-A], and the output value before that y[n-1-A].

[0086] The delay compensation unit 228 of the control device 22 calculates the current input value x[n+1-A] using, for example, a circular buffer. In this case, the delay compensation unit 228 uses a circular buffer capable of storing all the speed difference Vdif of the A-th quantity. The delay compensation unit 228 uses, for example, a circular buffer in which the speed difference Vdif older than the A-th quantity is continuously overwritten by the speed difference Vdif of the latest A-th quantity. The delay compensation unit 228 reads the current speed difference Vdif from the circular buffer. The current command calculation unit 222 adds the current speed difference Vdif to the previous speed integral value Intg”, multiplies the sum by the speed proportional gain Kp, and thereby calculates the current input value x[n+1-A].

[0087] Furthermore, the previous input value x[n-A], the input value x[n-1-A] two years ago, the previous output value y[n-A], and the output value y[n-1-A] two years ago can be the same values ​​used in the previous digital filter operation. Thus, the control device 22 can obtain the value of the current output value y[n+1-A].

[0088] Under this procedure, the control device 22 performs digital filter calculations A times, thereby obtaining the digital filter output value without delay, i.e., the current output value y[n]. The digital filter 223 notifies the delay compensation unit 228 that it has obtained the digital filter output value without delay. The delay compensation unit 228 then notifies the current ratio creation unit 81 that it has obtained the digital filter output value without delay. The current ratio creation unit 81 appropriately operates the current ratio Mag, thereby enabling energization to begin while ensuring the continuity of the current flow, thus reducing the impact on the movable part 3. Specifically, before obtaining the digital filter output value without delay, the current ratio creation unit 81 sets the current ratio Mag to "0" for the control device 22; upon obtaining the digital filter output value without delay, it sets the current ratio Mag to a value other than "0" for the control device 22 and begins energization.

[0089] The control quantity transmission and delay time compensation, such as the transmission of the speed integral value Intg and the filter control quantity Filt, are not limited to the digital filter 223, but can also be applied to other control functions such as the feedforward controller. The feedforward controller is included in at least one of the speed command calculation unit 211, the current command calculation unit 212, and the current control unit 214. That is, when driving the movable member 3, at least one of the speed command calculation unit 211, the current command calculation unit 212, and the current control unit 214 performs feedforward control using the feedforward controller control quantity.

[0090] In this case, the control quantity acquisition unit 227 of the control device 22 also obtains the feedforward controller control quantity from the control device 21. By performing control quantity transmission and delay time compensation for the feedforward controller's control quantity transmission processing, the control device 22 can also obtain a feedforward correction value without delay. Therefore, the control device 22 can achieve faster positioning time based on the feedforward correction value and further lower vibration using the vibration suppression function of the feedforward controller. The feedforward control performed by the control device 21 is the first feedforward control, and the feedforward control performed by the control device 22 is the second feedforward control.

[0091] As described above, in the linear motor system 10, the control device 22 receives the speed integral value Intg from the control device 21 for creating a current command corresponding to the speed command, and uses the speed integral value Intg to create the current command, thus reducing switching shock.

[0092] Furthermore, in the linear motor system 10, the control device 22 receives the filter control quantity Filt used by the digital filter 213 of the control device 21 from the control device 21, and performs digital filter calculations using the filter control quantity Filt'. As a result, the linear motor system 10 can suppress the resonant vibrations and switching shocks inherent in the structural elements of the linear motor system 10. Therefore, the linear motor system 10 can achieve further low vibration and improve its basic performance.

[0093] The digital filter 213 of the control device 21 is the first digital filter, and the digital filter 223 of the control device 22 is the second digital filter. In this case, the digital filter operation performed by the digital filter 213 of the control device 21 is the first digital filter operation, and the digital filter operation performed by the digital filter 223 of the control device 22 is the second digital filter operation.

[0094] Furthermore, in the linear motor system 10, the control device 22 uses the speed integral value Intg' and the filter control quantity Filt' after performing delay compensation for the speed integral value Intg' and the filter control quantity Filt', thus reducing the switching impact accompanied by delay.

[0095] After performing delay compensation for the speed integral value Intg' and the feedforward controller control quantity, the control device 22 can use the speed integral value Intg' and the feedforward controller control quantity to drive the movable part 3. This reduces the switching impact associated with the delay.

[0096] Furthermore, control devices 21-24 may not have a delay compensation unit 228. For example, in the case of control device 22, the speed integral value Intg' sent from the control quantity acquisition unit 227 is directly sent to the current command calculation unit 222. In this case, control device 22 performs digital filter calculation using the speed integral value Intg' and the filter control quantity Filt', thus suppressing the resonant vibration and switching shock inherent in the structural elements of the linear motor system 10.

[0097] Here, the hardware structure of control devices 21 to 24 will be described. Figure 5 This diagram illustrates an example of the hardware structure of the control device involved in the implementation of the embodiment. Furthermore, since control devices 21 to 24 have the same hardware structure, an example of the hardware structure of control device 22 will be described here.

[0098] The control device 22 can be implemented using a processor 100, a memory 200, an input device 300, and an output device 400. Examples of the processor 100 are CPUs (also known as Central Processing Units, microprocessors, microcomputers, DSPs (Digital Signal Processors)) or system LSI (Large Scale Integration) circuits. Examples of the memory 200 are RAM (Random Access Memory) or ROM (Read Only Memory).

[0099] The control device 22 is implemented by the processor 100 by reading and executing a computer-executable control program stored in the memory 200 for performing the actions of the control device 22. The program for performing the actions of the control device 22, i.e., the control program, can be described as the sequence or method by which the computer performs the actions of the control device 22.

[0100] The control program executed by the control device 22 is a modular structure that includes subtraction units 220 and 229, speed command calculation unit 221, current command calculation unit 222, digital filter 223, current control unit 224, multiplication unit 225, arithmetic unit 226, control quantity acquisition unit 227, and delay compensation unit 228. These modules are downloaded to the main storage device and generated on the main storage device.

[0101] Input device 300 receives position command Pcmd, current position Pos, current ratio Mag, speed integral value Intg, and filter control quantity Filt and sends them to processor 100. Memory 200 serves as temporary storage during various processes performed by processor 100. Memory 200 stores speed integral values ​​Intg, Intg', Intg'", and filter control quantities Filt, Filt', etc. Output device 400 outputs speed integral values ​​Intg, filter control quantities Filt, etc., to control device 23.

[0102] The control program can be provided as a computer program product, stored on a computer-readable storage medium in an installable or executable file format. Alternatively, the control program can be provided to the control device 22 via a network such as the Internet. Furthermore, the functions of the control device 22 can be implemented partly through dedicated hardware such as dedicated circuits, and partly through software or firmware.

[0103] As described above, in this embodiment, the speed integral value Intg' and the filter control quantity Filt' are exchanged between control devices 21 and 22. Furthermore, control device 22 calculates the speed integral value Intg' based on the speed integral value Intg' used by control device 21, and performs digital filter calculations using the internal values ​​of the digital filter calculations used by control device 21. Therefore, the switching shock that occurs when switching is performed by energizing the opposing movable member 3 can be sufficiently reduced.

[0104] Furthermore, the speed integral value Intg' and the feedforward controller control quantity are exchanged between control devices 21 and 22. Moreover, control device 22 calculates the speed integral value Intg' based on the speed integral value Intg' used by control device 21, and performs feedforward control using the feedforward controller control quantity used by control device 21. Therefore, the switching shock that occurs when switching is performed by energizing the opposing movable member 3 can be significantly reduced.

[0105] Furthermore, the control device 22 performs delay compensation for the speed integral value Intg' and the filter control quantity Filt', thus reducing the switching impact associated with the delay. Additionally, the control device 22 performs delay compensation for the speed integral value Intg' and the feedforward controller control quantity, thus reducing the switching impact associated with the delay.

[0106] The structure shown in the above embodiments is an example, and it can also be combined with other known technologies. Parts of the structure can be omitted or changed without departing from the main idea.

[0107] Explanation of the label

[0108] 1. Fixed component group; 2. Control device group; 3. Moving component; 4. Encoder reader; 5. Reading unit group; 6. Position information communication line; 7. Control information communication line; 8. Command creation unit; 9. Guide unit; 10. Linear motor system; 11-14. Fixed components; 21-24. Control device; 51-54. Encoder reading unit; 81. Current ratio creation unit; 82. Position command creation unit; 100. Processor; 200. Memory; 210, 219, 220, 229. Subtraction. The system includes: 211 and 221 speed command calculation unit; 212 and 222 current command calculation unit; 213 and 223 digital filter; 214 and 224 current control unit; 215, 225, 232 and 236 multiplication unit; 216 and 226 arithmetic unit; 227 control quantity acquisition unit; 228 delay compensation unit; 231 switch; 233 addition unit; 234 integration unit; 235 delay time determination unit; 300 input device; and 400 output device.

Claims

1. A linear motor system, characterized in that, have: First fastener; Second fastener; A movable member, which is configured opposite to the first fixing member and the second fixing member; The first control device, when the movable member is opposite to the first fixed member, performs energization on the first fixed member based on a first speed command or a first position command to the movable member, thereby driving the movable member. The second control device, when the movable member is opposite to the second fixed member, performs energization to the second fixed member based on a second speed command or a second position command to the movable member, thereby driving the movable member; as well as The instruction creation unit, when the movable member moves from the first fixed member to the second fixed member, sends the first speed instruction or the first position instruction to the first control device, and sends the second speed instruction or the second position instruction to the second control device, thereby causing the energization of the first fixed member by the first control device and the energization of the second fixed member by the second control device to be executed sequentially. The first control device has: The first current command calculation unit calculates the first current command value for the first fixed member based on a first speed integral value obtained by integrating the speed deviation between the first speed command and the actual speed of the movable member, i.e., the current speed; and The first digital filter performs first digital filter operations for the first current command value. The second control device has: The second current command calculation unit calculates the second current command value for the second fixed member based on the second speed integral value obtained by integrating the speed deviation between the second speed command and the actual speed of the movable member, i.e., the current speed. A second digital filter, which performs a second digital filter operation in response to the second current command value; and The control quantity acquisition unit acquires from the first control device the first speed integral value used by the first current command calculation unit, and the internal value in the first digital filter when the first digital filter performs the first digital filter operation. The second current command calculation unit calculates the second speed integral value based on the first speed integral value. The second digital filter performs the second digital filter operation using the internal value.

2. The linear motor system according to claim 1, characterized in that, The first control device performs first feedforward control when driving the movable part. The second control device performs second feedforward control when driving the movable part. The control quantity acquisition unit obtains from the first control device the feedforward controller control quantity used when the first control device performs the first feedforward control. The second feedforward control is performed using the control quantity of the feedforward controller.

3. A linear motor system, characterized in that, have: First fastener; Second fastener; A movable member, which is configured opposite to the first fixing member and the second fixing member; The first control device, when the movable member is opposite to the first fixed member, performs energization on the first fixed member based on a first speed command or a first position command to the movable member, thereby driving the movable member. The second control device, when the movable member is opposite to the second fixed member, performs energization to the second fixed member based on a second speed command or a second position command to the movable member, thereby driving the movable member; as well as The instruction creation unit, when the movable member moves from the first fixed member to the second fixed member, sends the first speed instruction or the first position instruction to the first control device, and sends the second speed instruction or the second position instruction to the second control device, thereby causing the energization of the first fixed member by the first control device and the energization of the second fixed member by the second control device to be executed sequentially. When driving the movable member, the first control device performs first feedforward control using a feedforward controller control quantity, and has a first current command calculation unit that calculates the first current command value for the first fixed member based on the first speed integral value obtained by integrating the speed deviation between the first speed command and the actual speed of the movable member, i.e., the current speed. The second control device performs second feedforward control when driving the movable member, and has the following features: A second current command calculation unit calculates the second current command value for the second fixed member based on the second speed integral value obtained by integrating the speed deviation between the second speed command and the actual speed of the movable member, i.e., the current speed. as well as The control quantity acquisition unit obtains the first speed integral value used by the first control device and the feedforward controller control quantity used by the first control device. The second current command calculation unit calculates the second speed integral value based on the first speed integral value. The second control device performs the second feedforward control by using the control quantity of the feedforward controller.

4. The linear motor system according to any one of claims 1 to 3, characterized in that, The second control device calculates the second speed integral value based on the first speed integral value. The second speed integral value is obtained by compensating for the delay time of the first speed integral value from when the first control device sends the first speed integral value to when the control quantity acquisition unit receives the first speed integral value.

5. The linear motor system according to claim 4, characterized in that, The second control device adds the speed deviation between the delay times to the first speed integral value, thereby calculating the second speed integral value.

6. The linear motor system according to any one of claims 1 to 3, characterized in that, The second control device is connected via a communication bus. The control quantity acquisition unit obtains the first speed integral value from the first control device via the communication bus.

7. The linear motor system according to any one of claims 1 to 3, characterized in that, The control quantity acquisition unit obtains the first speed integral value from the first control device via the instruction creation unit.

8. The linear motor system according to any one of claims 1 to 3, characterized in that, The first control device has a first digital filter that performs a first digital filter operation for the first current command value. The second control device has a second digital filter that performs a second digital filter operation for the second current command value. The control quantity acquisition unit obtains from the first control device the internal value of the first digital filter when the first digital filter performs the operation of the first digital filter. The second digital filter performs the second digital filter operation using the internal value.

9. A linear motor system, characterized in that, have: First fastener; Second fastener; A movable member, which is configured opposite to the first fixing member and the second fixing member; The first control device, when the movable member is opposite to the first fixed member, performs energization on the first fixed member based on a first speed command or a first position command to the movable member, thereby driving the movable member. The second control device, when the movable member is opposite to the second fixed member, performs energization to the second fixed member based on a second speed command or a second position command to the movable member, thereby driving the movable member; as well as The instruction creation unit, when the movable member moves from the first fixed member to the second fixed member, sends the first speed instruction or the first position instruction to the first control device, and sends the second speed instruction or the second position instruction to the second control device, thereby causing the energization of the first fixed member by the first control device and the energization of the second fixed member by the second control device to be executed sequentially. The first control device includes a first current command calculation unit, which calculates the first current command value for the first fixed member based on a first speed integral value obtained by integrating the speed deviation between the first speed command and the actual speed of the movable member, i.e., the current speed. The second control device has: The second current command calculation unit calculates the second current command value for the second fixed member based on a second speed integral value obtained by integrating the speed deviation between the second speed command and the actual speed of the movable member, i.e., the current speed; and The control quantity acquisition unit obtains the first speed integral value used by the first current command calculation unit from the first control device. The second current command calculation unit calculates the second speed integral value based on the first speed integral value.

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