JPH0424041A - Controlling system for positioning suspended object - Google Patents

Abstract

PURPOSE:To position a suspended object accurately by adding a position correction signal corresponding to a differential value between detecting signals of first and second position detectors to a position commanding signal to correct an error between both detecting signals. CONSTITUTION:The outputs P1, P2 of a position sensor 44 and height measurer 45 are converted to position data P3, P4 by position sensor converting means 15, 16. The position data P3 show the position of a servo motor 43 controlled by position commanding data F0 outputted from an upper controller 10, and the position data P4 show the position of an actual variable pulley 35. A difference between the position data P3 outputted from the position sensor converting means 15 and the position data P4 outputted from the position sensor converting means 16 is obtained to add a correction pulse Pc corresponding to the differential value to the position commanding data F0 and correct an error caused by discrepancies between both position data P3, P4. Thus, suspended objects can accurately be positioned at positions commanded by the position commanding data F0.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hanging object positioning control system for positioning hanging objects used in stage equipment, etc., at predetermined positions in the vertical direction. This invention relates to a hanging object positioning control system that allows objects to be positioned at accurate heights.

[Prior art]

In theaters, halls, etc., in order to increase the performance effect, there is a hanging device that suspends hanging objects such as decorations from beams above the stage and raises and lowers them to change the situation on the stage. It is used.

A typical example of such a hanging device is a single-point hanging device in which the hanging object is moved vertically using a wire (lobe).

The schematic structure of this one-point hanging device will be explained based on FIG. 6. FIG. 6 is a diagram showing a single point hanging device of the Flashen type, which has been used for a long time among single point hanging devices.

The rail 37 moves the single-point hanging trolley 30 parallel to the picture frame, and is attached to the gridiron at the top of the stage. In this figure, for convenience of explanation, the rail 31 is shown attached to the left and right side walls, but in reality, it is fixed to the lower part of the gridiron.

The one-point suspended trolley 30 has traveling pulleys 31 and 32 for moving along a rail 37 and wire pulleys 33 and 34 for guiding a wire 38. Variable pulley 35
is attached to the wire 38 between the wire pulleys 33 and 34, and moves in the vertical direction (up and down direction of the stage) according to the length of the wire 38. A one-point hanging hook 36 is provided at the lower end of the variable pulley 35 for hanging an object.

One end of the wire 38 is fixed to the side wall, and the other end is wound around the winch drum 39 in a plurality of times, and the wire 38 is attached to the counterweight 4.
Connected to 0. Therefore, the wire length from the fixed end to the winch drum 39 is variably controlled in accordance with the rotation of the winch drum 39.

The winch drum 39 is driven and controlled by a motor 43 coupled via a gearbox 41.

An electromagnetic brake 42 for stopping rotation of the winch drum 39 is provided between the motor 43 and the gearbox 41.

The height of the variable pulley 35 depends on the length from the fixed end of the wire 38 to the winch drum 39, so in this single point suspension device, the motor 43 is rotated to wind the wire 38 around the winch drum 39, and The length of the wire 38 from the fixed end to the winch drum 39 is controlled by moving the variable pulley 35 in the vertical direction. That is, by controlling the rotation of the motor 43, the height of the variable pulley 35 is changed, and the hanging object is positioned at a desired height.

At this time, since it is difficult to actually measure the length of the wire 38, the motor 43 is provided with a rotational position detection device or the like, and the length of the wire 38 is measured based on this position command signal.

[Problem to be solved by the invention]

However, the actual wire 38 has a fixed end and a wire pulley 34.
and between the pulley 33 and the winch drum 39 due to the weight of the wire itself, and the amount of deflection varies depending on the distance between them, the tensile force applied to the wire 38, and the like. That is, the weight of the hanging object hung on the single-point hanging hook 36 may change, or the single-point hanging trolley 30 may
7, the absolute length of the wire 38 itself does not change, but due to the change in the amount of deflection of the wire 38,
The height of the variable pulley 35 will change. Therefore, even if the length of the wire 38 can be accurately detected based on the rotational position of the motor 43, the actual height of the hanging object is not uniquely determined from the length of the wire 38.

Furthermore, due to changes in the vertical movement speed of the variable pulley 35 and use over time, the wire 38 stretches and the length of the wire itself changes. Therefore, even if the rotational position of the motor 43 is detected, the length of the wire 38 itself cannot be accurately detected.

Therefore, it is impossible to position the suspended object at an accurate height by simply measuring the length of the wire 38 based on the detection signal of the rotational position detector of the motor 43 as in the conventional method.

The present invention has been made in view of the above-mentioned points, and provides a hanging object positioning control system that can accurately position a hanging object whose movement is controlled in the vertical direction by wires simply by commanding the position to be positioned. The purpose is to provide.

[Means to solve the problem]

The hanging object positioning control system of the present invention includes a wire for vertically moving the hanging object, and a drum for moving the hanging object vertically by winding up the wire.
A motor that rotates the drum, a first position detector that detects the rotational position of the motor, a second position detector that detects the height of the hanging object, and a predetermined position at which the hanging object should be positioned. a motor control means for inputting a position command signal indicating a position and a detection signal from the first detector, and controlling the rotational position of the motor according to both signals;
The present invention is characterized by comprising a position correction means for adding a position correction signal corresponding to a difference value of detection signals from the detector to the position command signal.

[For production]

In order to move the hanging object in the vertical direction, it is sufficient to control the winding amount of the wire, that is, the length of the wire. The length of the wire can be measured by detecting the rotational position of the motor that rotates the drum.

Since the first position detector detects the rotational position of this motor, the rotational position of the motor is controlled based on the 5-position command signal and the detection signal of the first position detector, and the length of the wire, that is, the hanging object The height can be controlled quickly. On the other hand, the length of the wire often does not match the actual height of the suspended object due to elongation of the wire, and it is not possible to accurately position the suspended object only by the rotational position of the motor.

However, even if a second position detector is installed to detect the actual height of the suspended object in place of the first position detector, and the height of the suspended object is adjusted, there may be wires, etc. in the control loop system. Since it includes mechanical elements with very low rigidity, the gain of the control loop must be made small, and positioning also takes a lot of time.

Therefore, in the present invention, in addition to the first position detector, a second position detector for detecting the actual height of the hanging object is provided, and the first
If the detection signal of the first position detector and the detection signal of the second position detector do not match, a position correction signal corresponding to the difference value between the two is added to the position command signal, and the detection signal of the two is matched. Corrected the error when there was no such difference. Also,
During normal positioning control, the rotational position of the motor is controlled based on the detection signal from the first position detector.

The loop gain can be made sufficiently large and positioning can be performed at high speed. Further, the detection signal of the first position detector,
The actual height of the suspended object can be determined at an accurate position based on the detection signal of the second position detector.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an embodiment of the hanging object positioning control system of the present invention. In FIG. 1, the same parts as those in FIG. 6 are given the same reference numerals, so their explanation will be omitted.

The single point suspension device of FIG. 1 differs from that of FIG. 6 in that a height measuring device 45 for detecting the height of the variable pulley 35 is attached to the black trolley 30. This height measuring device 45 is
A height measuring wire 46 connected to the main shaft of the variable pulley 35
is wound around a wire drum having a constant diameter, and the length of the height measuring wire 46 is detected by detecting the rotational position of the wire drum rotated by the height measuring wire 46 with a sensor. Its configuration will be described later.

Further, as the motor 43, for example, a synchronous AC servo motor was used. A position sensor 44 for absolutely detecting the current position of the servo motor 43 is coupled to the servo motor 43. As this position sensor 44, for example,
An inductive phase shift type position sensor as disclosed in Japanese Patent Application Laid-open No. 70406 or Japanese Patent Laid-Open No. 58-106691 is used.

The host controller 10 is connected to the addition means 11 and receives position command data F indicating the target position of the servo motor 43.
O is output to the adding means 11. Further, the host controller 10 is connected to a serial communication interface 14, and outputs various data D1.

The position and speed control system 1 includes an adding means 11, a position control section 12, a speed control section 13, and a serial communication interface 1.
4, position sensor conversion means 15 and 16, speed calculation section 17, subtraction means 18, and correction pulse generation means 19.

The addition means 11 adds the correction pulse Pc of the correction pulse generation means 19 to the position command data FO of the host controller 10, and sends the added value to the position control unit 12 as the corrected position command data F1.

The position control unit 12 is connected to the addition means 11 and the position sensor conversion means 15, and receives corrected position command data F1 indicating the target position of the servo motor 43 and position data P3 indicating the current position of the servo motor 43. . Further, the position control section 12 is connected to a speed control section 13, which calculates a deviation between the corrected position command data F1 and position data P3, and sends a speed command signal F2 corresponding to the position deviation to the speed control section. Output to 13.

The position sensor conversion means 15 converts the output P1 of the position sensor 44 into position data P3 indicating the current position of the servo motor 43, and converts the output P1 of the position sensor 44 into position data P3 indicating the current position of the servo motor 43.
8 and also generates a phase signal P7 for controlling the switching position of the field, and outputs it to the serial communication interface 14.

The position sensor converting means 16 converts the position sensor output P2 of the height measuring device 45 provided on the Ikkuroko trolley 30 into position data P4 indicating the length of the height measuring wire 46, that is, the height of the variable pulley 35. , is output to the subtraction means 18.

The subtraction means 18 uses the position data P of the position sensor conversion means 15.
The position data P4 of the position sensor conversion means 16 is subtracted from 3 and the subtracted value is outputted to the correction pulse generation means 9 as error data P5.

That is, the error data P5 output from the subtraction means 18 calculates the error between the position of the servo motor 43 controlled by the device command data FO configured from the host controller 10 and the actual position of the variable pulley 35. This is the data shown.

The correction pulse generation means 19 inputs the error data P5 of the subtraction means 18, and outputs correction pulses Pc corresponding thereto to the addition means 11 at predetermined time intervals.

The reason for outputting at predetermined time intervals is to stably operate the control system (-black ratio device), which has low rigidity and includes the wire 38.

Therefore, the 1-position control unit 12 performs position control based on the position command data F1 obtained by adding the position command data FO and the correction pulse Pc.

The speed control section 13 is connected to the position control section 12 and the speed calculation section 17, and receives the speed command signal F2 from the position control section 12.
and a speed signal F3 indicating the current speed of the servo motor 43. The speed signal F3 is obtained by converting the position data P3 of the position sensor conversion means 15 by the speed calculation section 17. The speed calculation unit 17 inputs the position data P3 of the position sensor conversion means 15, and calculates the speed of the servo motor 43 by digital calculation based on the amount of change in the position data P3 per predetermined unit time. Furthermore, the speed control unit 13 is connected to a serial communication interface 14, calculates the deviation between the speed command signal F2 and the speed signal F3, and serially communicates the torque signal (current command signal) Tl of the servo motor 43 corresponding to this speed deviation. Output to interface 14.

The serial communication interface 14 is connected to the host controller 10, the speed control section 13, and the position sensor conversion means 15, and transmits various data D1, torque signal T1, and phase signal P6 from the host controller 10 to the current control system via the communication line. 2 serial communication interface 21
to be transmitted.

The serial communication interface 14 and the serial communication interface 21 are connected by a bidirectional communication line, and various data D1 from the host controller 1o and data D2 generated in the current control system 2 are exchanged with the host controller 10 for current control. It is exchanged with system 2.

The current control system 2 includes a serial communication interface 21 and a current control section 22.

Serial communication interface 21 is position speed control system 1
serial communication interface 14 and current control unit 2
2, torque signal T1 and phase signal P6
is received from the serial communication interface 14 and outputted to the current control unit 22 as a torque signal T2 and a phase signal P7, and various data D2 such as a status signal indicating the control state in the current control unit 22 is transmitted to the serial communication interface 14. do.

The current control unit 22 is connected to the serial communication interface 21 and the servo motor 43, and receives the torque signal T2.
and phase signal P7, and based on that, three-phase PW
The M signal is generated to drive the power transistor, and a drive current is supplied to each phase (U phase, ■ phase, W phase) of the servo motor 43. At this time, the current feedback signal T3 of the U-phase and V-phase current values is fed back to the current control unit 22 by the current check isolator CT. Current control section 2
2 amplifies the deviation between the torque signal (current command signal) T2 of each phase and the current feedback signal T3 of each phase and supplies a drive current to the servo motor 43.

Further, the serial communication interface 21 and the current control section 22 are connected by a data line, so that various data D2 can be exchanged between them.

The current control unit 22 has a function of detecting control states such as servo motor overload, power supply voltage drop, overcurrent, overvoltage, and overheat, and also outputs a servo status signal indicating these control states and a current amplifier. It has a memory that stores various data such as an ID code indicating the rating of the servo motor to be controlled and a motor rating code indicating the rating of the servo motor to be controlled. The data stored in the memory in the current control unit 22 is transferred to the data line and the serial communication interfaces 21 and 14 as the data D2 as needed.
It is transmitted to the upper controller 10 via. Note that the motor rating code is stored in the memory as a table. Therefore, by selecting a table number according to the rating of the servo motor connected via the communication line, the current control section 22 can control servo motors with different ratings. With this, even if the servo motor is replaced, the current control section can be changed to a control system suitable for the servo motor by simply changing the table number.

Next, the operation of this embodiment will be explained.

First, after configuring the hanging object positioning control system as shown in FIG. It is transmitted to the communication interface 21. The transmitted table number data is transmitted to the current control section 22 by the serial communication interface 21. Thereby, the current control section 22 specifies the rating of the servo motor 43 and functions as a current control section according to the rating of the servo motor 43.

The host controller 10 outputs position command data FO indicating the target position of the servo motor 43. In the position control unit 12, an addition means 11 adds a correction pulse Pc to the position command data FO.
The added position command data F1 is input. The position control section 12 outputs a speed command signal F2 based on the position command data F1 and the position data P3 to the speed control section 13.

The speed control unit 13 outputs a torque signal (current command signal) Tl corresponding to the speed command signal F2 and the speed signal F3 to the serial communication interface 14.

Transmission is performed between the serial communication interface 14 and the serial communication interface 21, and the serial communication interface 21 outputs the torque signal T2 and the phase signal P6 to the current control section 22. The current control unit 22 controls the drive current of the servo motor 43 based on the torque signal T2, the current feedback signal T3, and the phase signal P6.

Output P of position sensor 44 coupled to servo motor 43
The output P2 of the position sensor of the height measuring device 45 of the trolley 30 is fed back to the position and speed control system 1.

Outputs P1 and P2 of the position sensor 44 and height measuring device 45
are converted into position data P3 and P4 by position sensor conversion means 15 and 16. Position data P3 indicates the position of the servo motor 43 controlled by device command data FO constituted by the host controller 1o, and position data P4 indicates the actual position of the variable pulley 35. The error data P5 output from the subtraction means 18 is transmitted to the servo motor 43.
This shows the error caused as a result of rotation control. The correction pulse generating means 19 outputs a correction pulse Pc corresponding to the error data P5 to the position command data FO at predetermined time intervals to correct the error.

As described above, according to this embodiment, in addition to the position sensor 44 for detecting the rotational position of the servo motor 43, the height detector 45 for detecting the height of the variable pulley 35 is provided, and the position sensor is converted. The difference between the position data outputted from the means 15 and the device data P4 constituted by the position sensor converting means 16 is determined.

The position command data F is a correction pulse Pc corresponding to the difference value.
0 and corrects the error amount when the two position data do not match, so it is possible to accurately position the position commanded by the position command data FO.

In addition, during normal positioning control, the position sensor conversion means 15
Since the rotational position of the servo motor 43 is controlled based on the position data P3 of the wheel, and the variable pulley 35 is positioned at a predetermined position (height), the loop gain can be sufficiently large and positioning can be performed at high speed. I can do it.

If an abnormality such as overload, power supply voltage drop, overcurrent, overvoltage, or overheat occurs during this control, status signal data indicating these control states is transmitted from the current control unit 22 to the serial communication interface 21.
sent to. The data of this status signal is transmitted to the host controller 1 via the serial communication interface 14.
Sent to 0. The host controller 10 receives the data of this status signal and performs processing according to the type of the status signal.

When changing the servo motor 43 to a servo motor with a different rating, simply send the table number indicating the rating of the changed servo motor to the current control unit 22, and the current control unit 22 will change the rating according to the changed servo motor. Current control can be performed.

Although the upper controller 10 and the position/speed control system 1 are shown as being installed on the gridiron in the drawing, they are actually placed in the central control room of the stage equipment, and only the current control system 2 is installed. It is placed near the servo motor 43 via a communication line.

Next, the configuration of the height measuring device 45 for measuring the height of the variable pulley 35 will be explained. Fig. 2(a) shows the height measuring device 45.
FIG. 2(b) is a side view showing the height measuring device 45 with a part of the holding member removed.

The holding member 50 has a plurality of holes for holding each component of the height measuring device 45. A main shaft 52 and a sub-shaft 53 are attached to the shaft holding hole of the holding member 50. A spring winding tram 55a and a wire drum 55 are fixed to the main shaft 52 so as to rotate simultaneously. One end of the main shaft 52 is connected to a holding member 50 via a bearing, and the other end is rotatable by a position sensor 54. is maintained. A wire guide drum 58 and a spring drum 59 are rotatably attached to the auxiliary shaft 53.

The position sensor 54 is attached to the outside of the holding member 5o,
This is to absolutely check the rotational position of the main shaft 52, and the same induction type phase shift type position sensor as the position sensor 44 is used.

The wire tram 55 is a drum for winding the height measuring wire 46, and has a wire guide groove along the circumferential direction to prevent the height measuring wires 46 from overlapping each other when winding the wire. A drum 51 is provided on the upper side. The wire pressing drum 51 presses the wire against the wire drum 55 to eliminate uneven winding. This is because if the height measurement wires 46 are wound up in an overlapping manner, the diameter of the wire drum 55 becomes larger, making it impossible to accurately measure the height. Furthermore, the spring winding drum 55a winds up a spring 57 that applies a constant rotational force to the wire drum 55.

The wire guide drum 58 is rotatably attached to the sub-shaft 53 and guides the height measuring wire 46 from outside the measuring device to the wire drum 55. Although the wire guide drum 58 is shown to have a different diameter from the wire drum 55 in the drawing, it actually has the same diameter and has a wire guide groove like the wire drum 55. It goes without saying that if the wire drum 55 is arranged at a position where it protrudes from the outside of the measuring instrument like the wire guide drum 58, this wire guide drum 58 is not necessary.

The spring 57 is made of a thin, heat-treated material,
A ticket is attached in close contact with the spring drum 59, and one end of the ticket is fixed to the spring winding drum 55a with a screw.

The main shaft 52 rotates, and the band-shaped spring 57 is tightly wound around the spring winding drum 55a or the spring drum 59 and wound over the spring winding drum 55a.
That is, a constant rotational force is always applied to the main shaft 52.

The rotational force of the strip spring 57 is directly applied to the height measuring wire 46, and this becomes a force that pulls the height measuring wire 46. This tensile force on the height measuring wire 46 serves to ensure the linearity of the height measuring wire 46, so it is necessary to apply a tensile force according to the diameter of the height measuring wire 46. It is. For example, wire diameter 1.
A tensile force of approximately 500 g to 2 kg may be applied to 5 mm.

When actually measuring the height of the variable pulley 35 using this measuring device, connect the end of the height measurement wire 46 to the variable pulley 35.
fixed to the main shaft.

The feature of this height measuring device 45 is that an inductive phase shift type position sensor is used as the position sensor 54 for detecting the rotational position of the wire drum 55 that winds the height measuring wire 46. The point is that a band-shaped spring 57 is used to give a constant rotational force to the motor.

The operation of this height measuring device 45 will be explained.

The variable pulley 35 moves up and down depending on the length of the wire 38. When the variable pulley 35 rises, the height measuring wire 46 is wound around the wire drum 55 according to the rotational force of the band spring 57, and its length gradually becomes shorter. The absolute value also gradually decreases.

Conversely, when the variable pulley 35 descends, the height measuring wire 46 is uncoiled from the wire drum 55, its length gradually increases, and the absolute value of the position sensor 54 also gradually increases.

FIG. 3 is a diagram showing an absolute type position sensor consisting of an inductive phase shift type position sensor, which is an example of the position sensor 44 of FIG. 1 and the position sensor 54 of FIG. 2.

For details of this position sensor, please refer to Japanese Patent Application Laid-Open No. 57-70.
Since it is publicly known from Japanese Patent Application Laid-open No. 406 or Japanese Patent Application Laid-Open No. 106691/1982, a brief explanation will be given here.

The position sensor has a plurality of poles A-D arranged at predetermined intervals in the circumferential direction (
- for example, 90 degrees), and a rotor 74 inserted into the space of the stator 73 surrounded by various AD.

The rotor 74 is made of a shape and material that change various A-D glide roughtances depending on the rotation angle, and has an eccentric cylindrical shape, for example. Primary coils IA to ID and secondary coils 2A to 2D are wound around each type A to D of the stator 73, respectively. The first pair of poles A and C and the second pair of poles B and B, which are radially opposed to each other, are wound with coils so as to operate differentially. It is configured such that a roughtance change occurs.

The primary coils IA and IC wound around the first pole pair A and C are excited by a sinusoidal signal sinωt, and the primary coils IB and IC wound around the second pole pair B and D are excited by the sinusoidal signal sinωt. It is excited by a cosine signal cosωt. As a result, a composite output signal Y is obtained from the secondary coils 2A to 2D. This composite quality signal Y is a primary AC signal (primary coil excitation signal) sinω or cosω, which is a reference signal.
A signal Y=sin(ωt-θ) whose phase is shifted by an electrical phase angle corresponding to the rotation angle θ of the rotor 74 with respect to t.
It is.

Therefore, when using an inductive phase shift type position sensor as described above, the primary AC signal sinω or cos
It is necessary to include an alternating current signal generating means for generating ωt, and a phase difference measuring means for measuring the electrical phase shift θ of the composite output signal Y and calculating the rotor position data. The primary AC signal generating means and the phase difference measuring means are provided in the position sensor converting means 15 and 16.

FIG. 4 is a diagram showing an example of the position sensor conversion means 15 and 16 shown in FIG. 1. In the position sensor conversion means, a predetermined high-speed clock pulse CP is counted by a counter 76, and based on the output of the counter 76, a sine/cosine signal generation means 77 generates a sine signal sinω and a cosine signal CO8ωt, respectively. The output of the sine/cosine signal generating means 77 is output from the primary coils IA to I as described above.
D and each of the secondary coils 2A to 2D.

The composite output signal Y=sin (ω is -θ) of the secondary coils 2A to 2D is given to the zero cross detection means 78. The zero cross detection means 78 outputs a pulse L in synchronization with the timing when the electrical phase angle of the composite quality signal Y is zero. Pulse L is used as a latch pulse for latch circuit 79.

Therefore, the latch circuit 79 latches the count value of the counter 76 in response to the rise of the pulse L. counter 76
The period during which the count value of
Synchronize with the cycle. Then, the latch circuit 79 receives the reference AC signal sinωt and the composite output signal Y=sin(ωt−
The count value corresponding to the phase difference θ with respect to θ) is latched. Therefore, the latched value is output as digital position data Dθ. Note that the latch pulse L can also be used as a timing pulse as appropriate.

Further, among the values latched by the latch circuit 79, a value indicating the absolute position within one revolution of the servo motor is outputted as digital phase data P6, and is used for field switching position control.

Incidentally, the phase shift type position sensor as shown in FIG.

The composite output signals P1 and P2 have a phase difference based on the absolute positions of the servo motor 43 and the wire drum 55, and therefore have the characteristic that they are not easily affected by noise. Therefore, as shown in FIG.
When feeding back the combined output signals P1 and P2 from 5 to the position/velocity control system 1, direct feedback without using a communication line is not a problem because it is not affected by noise or the like. However, the combined output signals P1 and P2 of the position sensor 44 and height measuring device 45 may be fed back using a communication line such as a serial communication interface.

In addition, although FIGS. 3 and 4 are for detecting the range of one rotation in an absolute manner, it is preferable to combine a plurality of such absolute sensors to detect the absolute position over multiple rotations.

FIG. 5 is a diagram showing another embodiment of the present invention.

In FIG. 5, the same components as in FIG. 1 are denoted by the same reference numerals, so the explanation thereof will be omitted.

The difference between this embodiment and the one in Figure 1 is that Ikkuroko Toro υ30
servo motor 6 for moving along the rail 37
0, connect it to the axis switching unit 20, and connect it to the 3-phase (
The point is that the drive currents (U phase, ■ phase, W phase) and the sine signal, cosine signal, and composite output signal for the position sensor are switched by the axis switching unit 20 and driven alternately with the servo motor 43.

The moving wire 64 moves the Kuroko trolley 30 along the rail 37, and its both ends are fixed to the one-point suspended trolley 30, forming a loop via the drum 62 and pulley 63.

The drum 62 is coupled to the servo motor 60 and rotates in synchronization with the rotation of the servo motor 60.

When the drum 62 rotates and the moving wire 64 is wound around the drum 62, the loop-shaped moving wire 64 moves along the drum 62 and the pulley 63.

As the moving wire 64 moves, the one-point hanging trolley 30
also moves on the rail 37.

The axis switching unit 20 is a current control section 2 in the current control system 2.
2. It is connected to the position sensor conversion means 15, the host controller 10, the servo motor 43.60, and the position sensor 44.61 in the position and speed control system 1, and according to the axis switching signal channel from the host controller 10, The drive current is connected to each servo motor 43.60, and the signal for the position sensor is connected to each position sensor 44.61, respectively.

Therefore, one set of the servo motor 43.60 and the position sensor 44.61 is selectively connected to the position speed control system 1 and the current control system 2 according to the axis switching signal channel of the host controller 10, and each servo control loop form.

The axis switching unit 20 has switching elements provided corresponding to each servo motor 43.60 and each position sensor 44.61. By selectively conducting only the elements, only one set of servo motors and position sensors is selectively connected to the control loop.

At this time, if the ratings of the servo motors 43 and 60 are the same, it is only necessary to perform switching control while leaving the table number indicating the ratings of the servo motors constant.

Furthermore, if the ratings of the servo motors 43,60 are different, if the table number indicating the rating of the servo motor is transmitted via the communication line before controlling the servo motor, one current control system 2 It is possible to sequentially switch and control servo motors with different capacities.

According to the embodiment shown in FIG. 5, by controlling the rotational positions of the servo motors 43 and 60, the variable pulley 35 can be positioned at a desired position on the stage plane.

Note that when the single-point suspended trolley 30 is moved laterally as shown in FIG. 5, the error between the actual amount of movement and the detected value of the position sensor 61 is small, so There is no need to measure the actual position.

In the above embodiment, the height measuring device 45 is suspended from the trolley 30 at one point.
In the above description, the case where the Kuroko hook 36 is always installed and the positioning control is performed has been explained.
0 kg) is suspended, the height of the variable pulley 35 is changed in that state, and a table that correlates the detection data of the height measuring device 45 and the detection data of the position sensors 44 and 61 at that time is displayed for the weight. It is created for each time and stored in the memory within the position sensor conversion means 15. Thereafter, even without the height measuring device 45, the accurate height of the variable pulley 35 can be detected by reading a table corresponding to the weight of the hanging object according to the detection data of the position sensor 44. I can do it.

Further, in the above-described embodiments, a flasher-type hanging device using a pulley has been described, but the present invention can be similarly applied to a black thread device in which a load is vertically moved using a wire. Furthermore, the term "hanging object" in the present invention is not a stage decoration in a narrow sense, but is used in a broad sense that includes stage equipment that moves vertically by means of wires, such as curtains, screens, lighting 1 reflectors, and the like.

Note that the servo motor is not limited to a synchronous type servo motor, but may be an induction type AC servo motor. In that case, there is no need to generate phase signal P6.

Moreover, it goes without saying that the servo motor is not limited to an AC servo motor, but may also be of other types such as a DC servo motor.

Further, the position sensor is not limited to an inductive phase shift type sensor, but an optical absolute encoder, an incremental encoder, or other types of sensors may be used.

Furthermore, the communication line is not limited to electric cables, but optical cables may also be used.

〔Effect of the invention〕

According to the present invention, by controlling the length of the wire, it is possible to accurately position a hanging object that moves in the vertical direction at a desired position.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the hanging object positioning control system of the present invention, Fig. 2 (a) is a diagram showing the internal structure of the height measuring device in Fig. 1, and Fig. 2 (b) is a diagram showing an embodiment of the suspended object positioning control system of the present invention. A side view of the height measuring device shown in Fig. 1 with a part of the holding member removed; Fig. 3 shows an inductive phase shift type position sensor, which is an example of the position sensor shown in Figs. 1 and 2. 4 is a diagram showing an example of the position sensor conversion means of FIG. 1, FIG. 5 is a diagram showing another embodiment of the present invention, and FIG. 6 is a diagram showing a conventional one-point sensor. It is a figure showing a schematic structure of a hanging device. 1...Position speed control system, 2...Current control system, 11.
...Addition means, 12..Position control section, U3.Speed control section, 14.2.1..Sial communication interface, IS, 16..Position sensor conversion means, 18.Subtraction means, 19 ・Correction pulse generation means, 22 ・Current control unit. 30...-Kuroko Torillo, 31.32...Travelling pulley,
33.34・Wire pulley, 35・Variable pulley, 37・
・Rail, 38...Wire, 39・Winch drum,
43.60 Servo motor, 44.61 Position detector, 45 Brightness measuring device, 46 Wire for hole measurement, 54 Position sensor, 55 Wire drum, 57
...Take-up spring patent Rogandai Nisgy Co., Ltd. Patent attorney Yoshihito Iizuka Diagram (b) Diagram (a)

Claims (10)

[Claims] (1) A wire for vertically moving a hanging object, a drum for moving the hanging object vertically by winding this wire, a motor for rotating this drum, and a rotation position of this motor. a first position detector for detecting; a second position detector for detecting the height of the hanging object; a position command signal indicating a predetermined position at which the hanging object should be positioned; and detection of a position command signal by the first detector. a motor control means that inputs a signal and controls the rotational position of the motor according to both signals; A positioning control system for a hanging object, comprising: a position correction means for adding to a command signal; and a positioning control system for a suspended object. (2) The motor control means provides negative feedback of the detection signal of the first detector indicating the current position of the motor with respect to the position command signal indicating the predetermined position at which the hanging object should be positioned, and adjusts the position deviation thereof. position control means for outputting a speed command signal according to the speed command signal; and speed control means for negatively feeding back a feedback speed signal indicating the current speed of the motor with respect to the speed command signal, and outputting a current command signal according to the speed deviation thereof. The hanging object positioning control system according to claim 1, further comprising: a current control means for supplying a drive current to the motor according to the current command signal. (3) The suspended object positioning control system according to claim 2, wherein the speed control means and the current control means are connected through a bidirectional communication line. (4) The suspended object positioning control system according to claim 1, wherein the motor is a servo motor. (5) The wire is flushed using a one-point suspended trolley having a traveling pulley that moves on a rail and a wire pulley that guides the wire, and a variable pulley that moves vertically depending on the length of the wire. 2. The suspended object positioning control system according to claim 1, wherein the suspended object positioning control system constitutes a one-point hanging device. (6) The second position detector includes a measuring wire connected to the variable pulley, a wire drum for winding up the measuring wire, and a height for detecting the rotational position of the wire drum. 6. The suspended object positioning control system according to claim 5, comprising a position detector and a take-up spring that applies a constant rotational force to the wire drum, and is attached to the one-point hanging trolley. (7) The first position detector is an absolute type position sensor that detects the rotational position of the motor at an absolute position, and is displaced relative to a winding part,
a member that changes the magnetic resistance in the winding portion according to its relative position; 2. The suspended object control system according to claim 1, further comprising a phase shift type position sensor that generates an output AC signal having a phase shift. (8) The height position detector is an absolute type position sensor that detects the rotational position of the wire drum at an absolute position, and is displaced relative to the winding portion and the a member that changes the magnetic resistance in the windings according to their relative positions; the windings are excited by a plurality of phase-shifted primary alternating current signals; 7. The hanging object control system according to claim 6, comprising a phase shift type position sensor that generates an output AC signal with a phase shift. (9) A moving motor for moving the one-point suspended trolley along the rail and a third position detector for detecting the rotational position of the moving motor are provided, and the motor control means controls the motor and the moving motor. 6. The suspended object positioning control system according to claim 5, wherein the suspended object positioning control system is controlled by switching the motor. (10) A conversion in which a weight of a predetermined weight is suspended from the wire, the height of the weight is changed, and the detection signal of the first position detector and the detection signal of the second position detector are associated with each other at that time. By creating a table for each of the weights and reading out the conversion table corresponding to the weight of the suspended object according to the detection signal of the first position detector, the actual height of the suspended object is detected, and the height of the suspended object is detected. The hanging object positioning control system according to claim 1, wherein the hanging object positioning control system positions the hanging object at a predetermined position.