JP4568686B2 - Mobile device - Google Patents

Description

  The present invention relates to a moving apparatus having a moving body that moves linearly or rotates, and more particularly to a moving apparatus that performs position control of a moving body in a feedback control manner using a digital position signal.

  Many servo control systems that control the positioning of a moving body are digital systems using digital position signals. A moving device that uses a digital position signal to control the position of a moving body in a feedback control system is a phenomenon that was not noticeable with the analog control system. When the moving body fluctuates (moves back and forth) within a range corresponding to plus one unit and minus one unit of the minimum signal unit, fluctuation vibration occurs. The period of this fluctuation vibration is affected only by electrical parameters (position loop gain, velocity loop gain, time constant, PiD parameter, etc.) of the servo control system, and is not affected by the mechanical time constant.

  This fluctuation vibration does not cause a problem in accuracy by setting an appropriate positioning resolution in a general machine tool, but in a field where position fluctuation during machine operation is difficult, for example, in an ultra-precision field that requires submicron accuracy. It becomes a problem in mirror finishing.

  In order to avoid this, after positioning is completed, a control command is not issued in response to a change in the digital position signal within the range of several position detection units, and a so-called dead zone providing method or integration gain of the position control system is turned off. Techniques may be employed.

  However, since the method of providing the dead zone does not mean that the control system is disabled, the phenomenon that the moving body moves back and forth within the dead zone width when the cycle time becomes large only occurs. The fluctuation vibration does not disappear. In addition, when a force is applied to the moving body in one direction, the moving body is positioned at one end of the dead zone, so that the effect of increasing the accuracy of position control is small.

  Compared with the method of providing a dead zone, the effect is greater in the method of increasing the resolution of a digital position sensor that outputs a digital position signal, such as a linear scale that detects the position of a moving body. If the resolution of the digital position sensor increases, the fluctuation vibration width can be reduced accordingly. However, even in this case, the fluctuation vibration is not eliminated. In addition, there is a physical limit to increasing the resolution of the linear scale, and the higher the resolution of the linear scale, the more expensive the rotary encoder that detects the motor position.

Currently, the most reliable method for eliminating fluctuation vibration is to invalidate the mechanical clamp and servo control system control. However, ultra-precision machining, etc., when the value of the sub-micron ing and problems during the operation of mechanical clamping, moving body, since the allowable value or more, that would be moved is usually causes a low clamping force forced to many money Ikoto, there is danger of being moved by an external force. If the position of the moving body is displaced by an external force, there is a problem that the position cannot be returned or the position return is delayed.

  The present invention has been made to solve the above-mentioned problems, and suppresses the fluctuation vibration phenomenon after positioning completion, which the servo control system has desperately, to a value that does not cause a problem in practice, and at the same time, disturbs the disturbance. It is an object of the present invention to provide a moving apparatus that can quickly cope with the above-described problem and that improves the stability of the position after completion of positioning.

Mobile device according to the present invention, the mobile having solid and Jodai, a moving member provided movably with respect to the fixed base, a driving device for driving the movable body, and a control unit for controlling the drive device In the apparatus, first position detecting means for detecting the position of the moving body, and second position detecting means for detecting the position of the driving device having a resolution higher than that of the first position detecting means . a, the control device, wherein after the positioning based on the position information detected completed by the first position detecting means, disable the position control based on position information detected by said first position detecting means the have a row position control based only on the position information detected by the second position detection means, the signal feedback circuit of the first position detecting means, and a low-pass filter, gated buffer After the positioning is completed, the first low-pass filter is stopped, the gate of the gated buffer is closed, or the buffer value of the gated buffer is maximized. The position control based on the position information detected by the position detecting means is invalidated .

According to the moving device of the present invention, after the positioning is completed, the position control based on the position information by the first position detecting means for detecting the position of the moving body is invalidated and is higher than the resolution of the first position detecting means. Since the position control is performed based only on the position information by the second position detecting means that detects the position of the driving device with resolution, the fluctuation vibration width of the moving body is reduced according to the resolution of the second position detecting means. Become. In addition, in the position control by the second position detecting means , the fluctuation vibration width in the driving device is reduced due to the influence of the spring constant of the driving device, so that the effect of further reducing the fluctuation vibration width of the moving body can be expected. . As a result, according to the moving device of the present invention, the fluctuation vibration phenomenon after completion of positioning, which the servo control system has, is suppressed to a value that does not cause a problem in practice.

After the positioning is completed, the servo system based on the position information detected by the second position detecting unit operates, so that even if an external force within a certain level is applied to the moving body, the position shift does not occur. Can respond quickly to disturbances.

(Embodiment 1)
A moving apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

  The moving device of the present embodiment is a linear moving device, and includes a fixed base 11 having a linear movement guide portion 12 on the upper surface, a moving body 13 that moves linearly while being guided by the linear movement guide portion 12 of the fixed base 11, A driving device 20 that drives the moving body 13 and a control device 50 that controls the driving device 20 are included.

The fixed frame 11, a first position detection means for detecting the linear movement position of the moving body 13, the linear scale 14 is attached taken. The linear scale 14 inputs a digital position signal representing the linear movement position of the moving body 13 to the servo control unit 51 of the control device 50.

  The drive device 20 includes a feed screw 22 that is screw-engaged with a feed nut 21 attached to the movable body 13, bearings 23 and 24 that rotatably support the feed screw 22, a drive box 25, and a drive box 25. A servo motor (electric servo motor) 26 that is attached and rotationally drives the feed screw 22; and, if necessary, reduction gears 27 and 28, gear shafts 29 and 30 housed in a drive box 25, bearings 31 and 32, 33 or the like.

A rotary encoder 34 for detecting the rotational position of the servo motor 26 is attached to the rear end of the servo motor 26 as second position detecting means for detecting the position of the drive device 20. The rotary encoder 34 inputs a digital position signal indicating the rotational position of the servo motor 26 to the servo control unit 51 of the control device 50.

The resolution of the rotary encoder 34 must be sufficiently higher than the resolution of the linear scale 14 when converted to the feed amount of the moving body 13. When the resolution of the rotary encoder 34 is not sufficient, it is necessary to provide a speed reduction mechanism between the feed screw 22 and the servo motor 26. An example of this is a reduction gear train using gears 27 and 28.

As a second position detection means for detecting the position of the drive device 20, a separate rotary encoder 35 connected to the gear shaft 30 of the drive box 25 is used instead of the rotary encoder 34 directly connected to the servo motor 26. It may be used. The rotary encoder 35 inputs a digital position signal indicating the rotational position of the gear shaft 30 to the servo control unit 51 of the control device 50.

Further, the rotary encoder 34 of the servo motor 26 and the rotary encoder 35 of the gear shaft 30 are used in combination, and the rotary encoder 34 of the servo motor 26 is used as a position detection means dedicated to speed control (speed loop) in the servo control unit 51 to control the position. As the second position detecting means for (position loop), it is possible to construct a servo control system in which the rotary encoder 35 of the gear shaft 30 has a sufficiently high resolution.

  When the resolution of the rotary encoder 35 is insufficient, a speed increasing mechanism is provided by branching from the middle of the power transmission system from the servo motor 26 to the feed screw 22, and the rotary encoder 35 is attached to the rotary encoder 35. The feed amount per pulse can be reduced. Reducing the feed amount per pulse leads to reducing the amplitude of fluctuation vibration.

  In this case, it should be noted that the speed increasing mechanism has no backlash. If there is backlash, a dead zone occurs in the servo circuit of the rotary encoder 35 by the amount corresponding to the rotation angle of the backlash, and the original purpose cannot be achieved.

  If the rotary encoder 34 of the servo motor 26 has sufficient resolution, the separate rotary encoder 35 is unnecessary.

  When the resolution of the rotary encoder 34 of the servo motor 26 is insufficient, the encoder signal of the rotary encoder 34 is used only for speed feedback compensation, and a separate rotary encoder 35 having sufficient resolution is installed. These encoder signals may be used for position feedback compensation.

  The control device 50 includes a servo control unit 51 and a host control unit 52 using a microcomputer.

  The servo control unit 51 has a configuration in which a circuit to which a signal from the linear scale 14 is fed back and a circuit to which the rotary encoder 34 or 35 or both signals are fed back coexist.

  Conversion coefficient units 53, 54, and 55 are provided in the signal circuits of the linear scale 14 and the rotary encoders 34 and 35, respectively. When the conversion coefficient units 53, 54, and 55 have different sizes of one unit of each signal of the linear scale 14 and the rotary encoders 34 and 35 and one unit of the command signal MCMD depending on the conversion coefficients DMR14, DMR34, and DMR35, It corrects so that it may become equal value.

  The host control unit 52 includes a position command unit 56 that outputs a command signal MCMD. The command signal MCMD output from the position command unit 56 and the signals of the rotary encoders 34 and 35 are always added and subtracted by the comparator Cm1, and the deviation amount with respect to the command value is stored in the deviation counter 57 (ER1). Further, the command signal MCMD output from the position command unit 56 and the signal of the linear scale 14 are always added and subtracted by the comparator Cm4, and the deviation amount with respect to the command value is stored in the deviation counter 58 (ER3). The data stored in the deviation counters 57 and 58 is transmitted to the deviation monitoring unit 59 of the host control unit 52.

The signals of the linear scale 14 and the rotary encoders 34 and 35 that have passed through the conversion coefficient units 53, 54, and 55 are added and subtracted by the comparator Cm6, and the mutual deviation of both position detecting means is written in the mutual deviation counter 60 (ER4). The mutual deviation written in the mutual deviation counter 60 is transmitted to the deviation monitoring unit 59 of the higher order control unit 52 and is also passed to the gated buffer 61 which is the next functional unit.

  The set value of the gated buffer 61 can be changed by a signal from the constant / open / close command unit 63 of the host control unit 52, and the gate provided on the output side can be closed to shut off the circuit.

The low-pass filter 62 serves to remove the high-frequency component of the mutual deviation between the two position detecting means , and is sometimes called a first-order lag filter. The frequency change command unit 64 provided in the host control unit 52 is a function of changing the frequency for determining the signal flow suppression rate by the low-pass filter 62 and stopping the operation of the low-pass filter 62, that is, stopping the update of the mutual deviation amount. The stop command unit 65 can be used.

  The mutual deviation is added to the signal of the rotary encoder 34 or 35 by the comparator Cm5 after passing through the low-pass filter 62. Therefore, when the change rate of the mutual deviation is small, a signal having exactly the same value as the position detection value by the linear scale 14 is fed back to the comparator Cm2 of the servo control system (position loop). That is, according to this circuit configuration, the final positioning of the moving body 13 is performed by the position signal of the linear scale 14.

  The comparator Cm2 performs addition / subtraction between the command signal MCMD output from the position command unit 56 and the signal of the comparator Cm5, and the deviation of the signal (position feedback signal) of the comparator Cm5 with respect to the command signal MCMD is a deviation counter 68 (ER2). Is written to.

  The speed / acceleration / deceleration time constant setting unit 66 in front of the comparator Cm2 controls the speed and acceleration / deceleration of the return operation when the moving body 13 is forcibly dragged in a state different from that during normal movement. Is to do. The return operation speed and acceleration / deceleration by the speed / acceleration / deceleration time constant setting unit 66 can be changed by a constant / curve command unit 67 of the host control unit 52.

  The deviation of the deviation counter 68 is sent to the comparator Cm3 via the gain setter 70. The comparator Cm3 calculates a deviation between the speed command with respect to the output of the gain setting device 70 and the speed feedback value obtained by differentiating the signal of the rotary encoder 34 by the differentiator 75, and passes the deviation to the speed controller 71. . The speed controller 71 outputs a current command to the servo amplifier 72. As a result, the current flowing through the servo motor 26 is controlled by the servo amplifier 72.

  The deviation counter 68 sends the written deviation to the deviation monitoring unit 59 of the upper control unit 52. The deviation monitoring unit 59 of the host control unit 52 determines whether or not the deviation from the deviation counter 68 is zero or within a preset value by the positioning impose check function. If the deviation from the deviation counter 68 is zero or within a preset value, the deviation monitoring unit 59 determines that the positioning has been completed and outputs a positioning completion (imposition) signal.

  In the host control unit 52, when a positioning completion signal is output, the function stop command unit 65 outputs a function stop signal to the low-pass filter 62, or the constant / open / close command unit 63 closes the gate of the gated buffer 61 or sets the buffer value. A command signal for maximizing (maximizing) is output to the gated buffer 61.

  Thereby, the function of the low-pass filter 62 is stopped (mutual deviation update is stopped), the gate of the gated buffer 61 is closed, and the buffer value is maximized, and the mutual deviation circuit using the position signal of the linear scale 14 is cut off. As a result, the output value of the low-pass filter 62 becomes a constant value, and the feedback signal of the servo control system (position loop) becomes a value obtained by adding a constant value to the signal of the rotary encoder 34 or 35.

  That is, after the positioning is completed, the position control based on the position information detected by the linear scale 14 becomes invalid, and the position control is performed based only on the position information detected by the rotary encoder 34 or 35.

  It should be noted that the position control based on the position information detected by the linear scale 14 is invalidated by a plurality of combinations of the function stop of the low-pass filter 62, the gate closing of the gated buffer 61, and the buffer value maximization of the gated buffer 61 Also good.

  Therefore, after the positioning is completed, the fluctuation vibration of the servo control system becomes the fluctuation vibration due to the signal of the rotary encoder 34 or 35. That is, the single amplitude of the fluctuation vibration after the positioning is completed corresponds to the minimum resolution of the rotary encoder 34 or 35. If the rotary encoder 34 or 35 has a sufficiently high resolution, the fluctuation vibration width can be reduced. it can.

  For example, when a servo motor 26 incorporating a rotary encoder 34 of 100,000 pulses per rotation is directly connected to the feed screw 22 having a pitch of 10 mm, the feed amount of the moving body 13 per pulse of the rotary encoder 34 (= fluctuation vibration fluctuation). The half amplitude) is 0.1 μm, and the fluctuation vibration width A is plus or minus 0.1 μm, depending on the movement phenomenon of the moving body 13. This fluctuation vibration width can be ignored in practice.

  Furthermore, the fluctuation vibration width can be expected to be further reduced depending on the balance between the spring constant K of the feed drive system and the feed resistance value Ff. For example, when the spring constant K of the feed drive system is 400 N / μm (= 4 N / 0.01 μm) in terms of feed direction (straight line) and the feed resistance value Ff is 50 N, the fluctuation vibration piece amplitude (rotary rotary) by the servo control system If the feed amount of the movable body 13 per pulse of the encoder 34) A = 0.10 μm, the force acting on the spring system of the feed drive system is 40 N, which is smaller than the feed resistance value Ff = 50 N. The body 13 does not move, and only the spring system of the feed drive system is contracted or stretched (elastically deformed). That is, if A · K <Ff, the moving body 13 does not fluctuate.

  Therefore, the feed resistance Ff of the mobile body 13, the spring constant K of the feed drive system of the mobile body 13, and the feed amount A of the mobile body 13 per pulse of the rotary encoder 34 satisfy A · K <Ff. It is preferable that they are set as follows.

  When the feedback circuit based on the signal of the linear scale 14 is cut off, the output of the low-pass filter 62 becomes a constant value. Therefore, the servo control system does not operate because the mutual deviation counter 60 already has no remaining amount. . That is, the moving body 13 is not unnecessarily moved by a deviation resulting from a difference in accuracy that may occur between the linear scale 14 and the rotary encoders 34 and 35.

  After the positioning is completed, the moving body 13 is substantially stopped in a fluctuation vibration state having a much smaller amplitude than that in the case where the positioning is held by the signal of the linear scale 14. However, in this state, when an external force P greater than the feed resistance value Ff acts on the moving body 13, the moving body 13 is moved. Depending on the magnitude of the external force P, the moving body 13 may have a minimum detection unit of the linear scale 14. There may be a shift in the amount of movement that exceeds the limit. In general, the linear scale 14 has a minimum detection unit equal to a desired positioning accuracy or about half, and therefore, the phenomenon of the displacement movement of the moving body 13 cannot be overlooked.

  Here, the displacement amount of the moving body 13 will be described as a specific example. Spring constant K of the feed drive system = 400 N / μm, feed resistance value Ff = 50 N of the moving body 13, external force P = 1000 N, resolution S of the linear scale 14 S = 1.0 μm, resolution R of the rotary encoder 34 or 35 R = 0. Assuming 1 μm, the load Pf acting on the feed drive system is expressed by the following equation (1).

Pf = P-Ff = 1000N-50N = 950N (1)
Assuming that the servomotor 26 is locked and does not move, the deflection of the feed drive system = the deviation Δχ of the moving body 13 is expressed by the following equation (2).

Δχ = Pf / K = 950 N / 400 N / μm = 2.375 μm (2)
Actually, the servo motor 26 is not completely locked and has servo rigidity and response frequency determined by the factors of the mechanical system and electrical system, so that the external force acts on the moving body 13 at a speed faster than the response frequency. Then, since the servomotor 26 is reversed, the moving body 13 is moved by an amount larger than the above-described deviation amount Δχ.

  In order to cope with such a situation, the servo control system of the mobile device of the present embodiment has the following configuration and characteristics.

  After the positioning is completed, the position of the moving body 13 is controlled in a feedback compensation manner by a signal from the rotary encoder 34 or 35. Under this state, the signal of the linear scale 14 is invalidated in the servo control system, but the signal of the linear scale 14 itself exists, and the deviation counter 68 of the feedback circuit (position loop) has the command signal MCMD and the moving body. 13 represents the deviation (deviation) from the current value of 13, that is, the signal value of the linear scale 14.

  The host control unit 52 includes a deviation monitoring unit 59 that monitors the deviation amount of the stop position of the moving body 13 after the positioning is completed. The deviation monitoring unit 59 constantly monitors the deviation counter 58 and the signal of the linear scale 14 (the stored value of the mutual deviation counter 60), and the deviation between the command signal MCMD and the signal of the linear scale 14, that is, the moving body 13 It is checked whether or not the deviation amount of the stop position is within a preset threshold value (excessive scale deviation check during operation). When the amount of deviation exceeds a preset threshold value, the special servo control unit 69 provided in the upper control unit 52 recognizes that it is necessary and sends a correction signal.

  By sending this correction signal, the constant / open / close command unit 63 and the function stop command unit 65 of the host control unit 52 from the constant / open / close command unit 65 and the function stop command unit 65 are re-validated in the servo control system. A control signal is sent to bring 62 to its original operating state. Thereby, the position control based on the signal of the linear scale 14 becomes effective.

  Thus, as in the positioning, what is necessary when the servo control system is switched is accumulated in the gated buffer 61 so that the servo control by the signals of both the rotary encoder 34 or 35 and the linear scale 14 coexists. This is a function for preventing the occurrence of a shock in the driving device 20 and the moving body 13 by instantaneously rotating the servo motor 26 when the feedback compensation amount enters the position loop step by step. The speed / acceleration / deceleration time constant setting unit 66 and the constant / curve command unit 67 control this function.

  As a result, the movement command amount that has flowed into the step shape enters the servo control system (position loop) with the speed, acceleration, and curve specified by the constant / curve command section 67, and a shock is applied to the drive device 20 and the moving body 13. Occurrence is prevented.

  The same effect can be obtained by setting appropriate values in the low-pass filter 62 and the frequency change command unit 64.

  In the present embodiment, a torque variable control command unit 73 that can change the torque of the servo motor 26 via the servo amplifier 72 is provided in the host control unit 52 in addition to the constant torque control command unit 74. Yes. Thereby, in addition to the normal servo control in which the output torque is controlled based on the position signal and the load, it is possible to control the torque as necessary.

  If this control function is used, the moving body 13 can be fed and moved with a predetermined torque until the moving body 13 reaches the command position. In addition, the servo control system is invalidated by positioning the servo control system. Thus, while the position is controlled only by the signal of the rotary encoder 34 or 35, the movable body 13 can be held at a fixed position with a predetermined torque.

  Further, in a state where the position control is performed only by the signal of the rotary encoder 34 or 35, the deviation (displacement) of the moving body 13 becomes large, and the control returns to the position control using the signal of the linear scale 14 together. When the control to return to the position is performed, the torque control can be used in combination with the position control method subjected to acceleration / deceleration time constant processing or independently. The predetermined torque mentioned here includes not only a constant torque but also a torque that is arbitrarily changed.

  Thereby, in the return control of the moving body 13, the operation of returning the displacement amount of the stop position of the moving body 13 to zero or a predetermined value is performed by a specified constant torque or a variable torque method that changes at a specified rate. Can do.

(Embodiment 2)
A mobile device according to a second embodiment of the present invention will be described with reference to FIG.

In this embodiment, two sets of linear movement guide portions 12R and 12L are provided in parallel with each other on the fixed base 11, and a moving body 13R that linearly moves while being guided by the linear movement guide portion 12R, and a linear movement guide portion. A moving body 13L that is guided by 12L and moves linearly is provided in parallel. The moving bodies 13R and 13L are connected to each other by a connecting body 13C and can take a form of linear movement integrally.

  A driving device 20R that drives the moving body 13R and a driving device 20L that drives the moving body 13L are individually provided. The drive devices 20R and 20L are controlled by the control device 500 as a whole.

A fixed base 11, the mobile 13R, as the first position detecting means for detecting the linear movement position of each of 13L, the linear scale 14R, 14L are attach. The linear scale 14R inputs a digital position signal representing the linear movement position of the moving body 13R to the control device 500, and the linear scale 14L inputs a digital position signal representing the linear movement position of the moving body 13L to the control device 500.

  The drive devices 20R and 20L are each configured similarly to the drive device 20 of the first embodiment, and feed screws 22R and 22L that are screw-engaged with feed nuts 21R and 21L attached to the moving bodies 13R and 13L, The drive boxes 25R and 25L and servomotors 26R and 26L that are attached to the drive boxes 25R and 25L and rotationally drive the feed screws 22R and 22L are configured.

At the rear end of the servo motor 26, rotary encoders 34R and 34L for detecting the rotational positions of the servo motors 26R and 26L are attached as second position detecting means for detecting the positions of the drive devices 20R and 20L. The rotary encoders 34R and 34L input digital position signals representing the rotational positions of the servo motors 26R and 26L to the control device 500, respectively.

  The resolution of the rotary encoders 34R and 34L must be sufficiently higher than the resolution of the linear scales 14R and 14L, as in the first embodiment.

The driving devices 20R and 20L are provided separately as a second position detecting means for detecting the positions of the driving devices 20R and 20L as needed, connected to gear shafts (not shown) in the driving boxes 25R and 25L. Rotary encoders 35R and 35L may be attached. The resolution of the rotary encoders 35R and 35L must be sufficiently higher than the resolution of the linear scales 14R and 14L, as in the first embodiment.

Although detailed illustration of the control device 500 is omitted, a servo control unit equivalent to the servo control unit 51 of the control device 50 shown in the first embodiment is used for the servo motor 26R and the servo motor 26L. , Have two cars. The control device 500 has one upper control unit equivalent to the upper control unit 52 of the control device 50 shown in the first embodiment.

  This host control unit controls both the servo control unit for the servo motor 26R and the servo control unit for the servo motor 26L, and controls the two moving bodies 13R and 13L at the same position with the same speed and acceleration / deceleration. Sends a positioning command to each servo controller.

  When the difference between the positions of the moving bodies 13R and 13L exceeds a set threshold value, the control device 500 moves the selected side to the nearest positioning position automatically or by a signal from the host controller. It has a function of returning the position of the body 13R or 13L.

  In the control device 500, the host controller can send a command for positioning only to one of the servo controller for the servo motor 26R and the servo controller for the servo motor 26L. In this case, only one of the two moving bodies 13R and 13L is positioned at the designated position with the designated speed / acceleration / deceleration.

  Except for the above, position control is performed as in the first embodiment. Therefore, also in Embodiment 2, the same operations and effects as in Embodiment 1 can be obtained.

(Embodiment 3)
Embodiment 3 of the moving apparatus according to the present invention will be described with reference to FIG. 4, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

The third embodiment is of a hydraulic / electric servo type. A driving device 80 for driving the moving body 13 includes a hydraulic cylinder device 81 and an electric motor / pump type hydraulic servo for controlling the amount of oil sent to the hydraulic cylinder device 81. A valve 87 or an electromagnetic hydraulic servo valve 88 and a hydraulic supply source unit 89 are included. Electric motor Hydraulic servovalve 87 includes an oil pump 91 driven by an electric servo-motor 90.

  In the hydraulic cylinder device 81, the cylinder portion 82 is fixed on the fixed base 11, and the tip of the piston rod 83 is directly connected and fixed to the moving body 13 by a bracket 84 having an appropriate spring constant. A linear scale 86 is connected to the rear rod 85 of the hydraulic cylinder device 81 as first position detecting means for detecting the position of the moving body 13. The linear scale 86 inputs a digital position signal indicating the linear movement position of the moving body 13 to the control device 50.

  The linear scale 86 may be provided so as to directly detect the position of the moving body 13 as in the first embodiment.

The electric servo motor 90 of the electric motor / pump hydraulic servo valve 87 is provided with a rotary encoder 92 for detecting the rotational position of the electric servo motor 90 as a second position detecting means for detecting the position of the driving device 20. Yes. The rotary encoder 92 inputs a digital position signal indicating the rotational position of the electric servomotor 26 to the control device 50.

  The resolution of the rotary encoder 92 must be sufficiently higher than the resolution of the linear scale 86 as in the first embodiment.

When the electromagnetic hydraulic servo valve 88 is used, a position detector 93 for detecting the spool position of the hydraulic servo valve 88 is attached to the hydraulic servo valve 88 as the second position detecting means for detecting the position of the drive device 20. It is done. The position detector 93 inputs a digital position signal indicating the spool position of the hydraulic servo valve 88 to the control device 50. In this case, the resolution of the position detector 93 requires that one unit for detecting the spool position of the hydraulic servo valve 88 is sufficiently smaller than one unit of the linear scale 86.

The control device 50 according to the third embodiment is configured in the same manner as the control device 50 according to the first embodiment, and controls the electric servo motor 90 or the hydraulic servo valve 88. Therefore, also in the third embodiment, position control is performed in the same manner as in the first embodiment, and the same operations and effects as in the first embodiment are obtained.

(Embodiment 4)
The fourth embodiment of a mobile device according to the present invention will be described with reference to FIG.

  The fourth embodiment is a rotary type moving device. In the moving device of this embodiment, a rotary table (rotary moving body) 102 is rotatably provided on a fixed base 101 in a form supported by the fixed base 101 by a hydrostatic bearing (not shown).

  A rotation position detector 103 is attached to the fixed base 101 as first position detection means for detecting the position of the rotation table 102. The rotational position detector 103 inputs a digital position signal indicating the rotational position of the rotary table 102 to the control device 50.

  A driving device 110 for rotating the rotary table 102 is attached to the fixed base 101. The drive device 110 includes a friction drive type speed reducer (not shown) provided in the drive box 111 and a servo motor (electric servomotor) 112 attached to the drive box 111.

A rotary encoder 113 that detects the rotational position of the servo motor 112 is attached to the servo motor 112 as a second position detection unit that detects the position of the driving device 110. The rotary encoder 113 inputs a digital position signal indicating the rotational position of the servo motor 112 to the control device 50.

  The resolution of the rotary encoder 113 must be sufficiently higher than the resolution of the rotational position detector 103.

The drive device 110 has a separate rotary encoder 114 connected to a shaft (not shown) of the speed reduction unit in the drive box 111 as second position detection means for detecting the position of the drive device 110 as necessary. May be attached. The resolution of the rotary encoder 114 must be sufficiently higher than the resolution of the rotational position detector 103.

  The control device 50 according to the fourth embodiment is configured similarly to the control device 50 according to the first embodiment, and controls the servo motor 112. Therefore, also in the fourth embodiment, position control is performed in the same manner as in the first embodiment, and the same operations and effects as in the first embodiment are obtained.

It is a perspective view which shows Embodiment 1 of the moving apparatus by this invention. It is a block diagram which shows Embodiment 1 of the moving apparatus by this invention. It is a perspective view which shows Embodiment 2 of the moving apparatus by this invention. It is a perspective view which shows Embodiment 3 of the moving apparatus by this invention. It is a perspective view which shows Embodiment 4 of the moving apparatus by this invention.

Explanation of symbols

11 fixed base 12, 12R, 12L linear movement guide unit 13, 13R, 13L moving body 14, 14R, 14L linear scale 20, 20R, 20L drive unit 21, 21R, 21L feed nut 22, 22R, 22L feed screw 23, 24 Bearing 25, 25R, 25L Drive box 26, 26R, 26L Servo motor 27, 28 Gear 29, 30 Gear shaft 31, 32, 33 Bearing 34, 34R, 34L Rotary encoder 35, 35R, 35L Rotary encoder 50, 500 Control device 51 Servo control unit 52 Host control unit 53, 54, 55 Conversion coefficient unit 56 Position command unit 57, 58 Deviation counter 59 Deviation monitoring unit 60 Mutual deviation counter 61 Gated buffer 62 Low pass filter 63 Constant / open / close command unit 64 Frequency change command unit 65 Function stop fingers Command section 66 Speed / acceleration / deceleration time constant setting unit 67 Constant / curve command section 68 Deviation counter 69 Special servo control section 70 Gain setting section 71 Speed controller 72 Servo amplifier 73 Torque variable control command section 74 Constant torque control command section 75 Differential Cm1 to Cm6 Comparator 80 Drive device 81 Hydraulic cylinder device 82 Cylinder part 83 Piston rod 84 Bracket 85 Rear rod 86 Linear scale 87 Electric motor / pump type hydraulic servo valve 88 Electromagnetic hydraulic servo valve 89 Hydraulic supply source unit 90 Electric servo Motor 91 Oil pump 92 Rotary encoder 93 Position detector 101 Fixed base 102 Rotary table 103 Rotational position detector 110 Drive unit 111 Drive box 112 Servo motor 113, 114 Rotary encoder

Claims (5)

In a moving device having a fixed base, a movable body provided movably with respect to the fixed base, a drive device for driving the movable body, and a control device for controlling the drive device,
First position detecting means for detecting the position of the moving body;
Second position detection means for detecting a position of the driving device having a resolution higher than that of the first position detection means ;
The control device, wherein after the positioning based on the position information detected completed by the first position detecting means, disable the position control based on position information detected by said first position detecting means, the second There line position control based only on the position information detected by the second position detecting means,
The signal feedback circuit of the first position detecting means is provided with a low-pass filter and a gated buffer. After positioning is completed, the function of the low-pass filter is stopped, the gate of the gated buffer is closed, and the gate is attached. Disabling position control based on position information detected by the first position detecting means by any one or a combination of maximization of the buffer value of the buffer;
A mobile device characterized by that. In a moving device having a fixed base, a movable body provided movably with respect to the fixed base, a drive device for driving the movable body, and a control device for controlling the drive device,
First position detecting means for detecting the position of the moving body ;
Second position detection means for detecting a position of the driving device having a resolution higher than that of the first position detection means;
The control device, wherein after the positioning based on the position information detected completed by the first position detecting means, disable the position control based on position information detected by the front Symbol first position detection means, Performing position control based only on position information detected by the second position detecting means,
The control device includes a deviation monitoring unit that monitors a deviation amount of the stop position of the moving body, and when the deviation amount of the stop position of the movable body exceeds a preset threshold, the first position detection unit The position control based on the position information detected by is made effective, and the return control for returning the shift amount of the stop position of the moving body to zero or within a predetermined value is performed.
It shall be the said moving device. In a moving device having a fixed base, a movable body provided movably with respect to the fixed base, a drive device for driving the movable body, and a control device for controlling the drive device,
First position detecting means for detecting the position of the moving body;
Second position detection means for detecting a position of the driving device having a resolution higher than that of the first position detection means;
The controller disables the position control based on the position information detected by the first position detecting means after the positioning based on the position information detected by the first position detecting means is completed, and Performing position control based only on position information detected by the position detecting means of 2,
The signal feedback circuit of the first position detecting means is provided with a low-pass filter and a gated buffer. After positioning is completed, the function of the low-pass filter is stopped, the gate of the gated buffer is closed, and the gate is attached. Disabling position control based on position information detected by the first position detecting means by any one or a combination of maximization of the buffer value of the buffer;
The control device includes a deviation monitoring unit that monitors a deviation amount of the stop position of the moving body, and when the deviation amount of the stop position of the movable body exceeds a preset threshold, the first position detection unit The position control based on the position information detected by is made effective, and the return control for returning the shift amount of the stop position of the moving body to zero or within a predetermined value is performed .
It shall be the said moving device. The mobile device according to claim 2 or claim 3,
In the return control, the operation of returning the displacement amount of the stop position of the moving body to zero or within a predetermined value is performed according to a specified speed and acceleration / deceleration time constant .
It shall be the said moving device. The mobile device according to claim 2 or claim 3,
In the return control, an operation of returning the amount of deviation of the stop position of the moving body to zero or a predetermined value is performed by a specified constant torque or a variable torque method that changes at a specified rate .
It shall be the characteristic of the transfer DoSo location.

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