JPH0323470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inter-reel direct tape feeding type magnetic tape device, etc. (hereinafter referred to as an inter-reel direct tape feeding device) that directly transfers magnetic tape, etc. between two reels. The present invention relates to a device for detecting tape conditions such as tape tension and tape speed (including linear objects such as wires).

Conventionally, tension arms have been widely used to detect tape tension. This method determines the tape tension based on the rotation angle of the arm when the force of the spring urging the tension arm and the tape tension are balanced. This device has the drawback that the response time of the tension detection signal is slow and a large tension detection error occurs in high acceleration conditions such as when starting and stopping the tape. Another disadvantage is that the mechanical vibration of the tension arm is transmitted to the tape, and this vibration makes the contact between the tape and the head unstable, making data recording and playback unstable. .

Conventionally, a speed detection roller is used to detect tape speed. That is, the roller is rotated by the frictional force between the tape and the roller, and the tape speed is determined from the number of rotations of the roller. In this case, there is a drawback that slips are likely to occur between the roller and the tape during high acceleration such as when the tape is started or stopped, and detection accuracy is poor.

An object of the present invention is to detect tape tension, speed, etc. by using a simulation circuit that simulates the dynamic characteristics of a take-up motor and a supply motor using an electric circuit, without using mechanical means, in order to detect the state of the tape. It is an object of the present invention to provide a tape state signal detecting device that can obtain accurate detection output even during high acceleration by calculating and outputting the state.

The detection device of the present invention is a reel-to-reel direct tape speeding device that includes a take-up motor that drives a take-up reel and a supply motor that drives a supply reel. a simulating circuit that simulates and outputs the states of the two motors and tape states such as tape tension and tape speed using an electric circuit based on current; a motor state output section that detects the states of the two motors; an error detection circuit that detects a difference between a motor state signal output from the detection section and a motor simulation state signal output from the simulation circuit; and an error detection circuit that multiplies the output of the error detection circuit by a coefficient output from a coefficient setting circuit described later. Coefficient settings for calculating the tape transport amount based on the outputs of the error multiplier circuit and the motor status detection section, calculating the inertia and tape winding diameter of both motors, and creating and outputting various coefficients necessary for the operation of the error multiplier circuit and the simulation circuit. An output of the error multiplication circuit is inputted to the simulation circuit as an error correction signal, and the simulation circuit performs a correction operation based on the error correction signal.

Note that the motor state detection section can be easily configured by a motor rotation angle detector, a motor rotation speed detector, or a combination thereof. Then, the error detection section detects an error by comparing these outputs with a corresponding output signal of the simulation circuit.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in which the error detection circuit is constituted by a circuit for detecting errors in rotation angle signals. That is, the tape 1 is taken up on the take-up reel 2.
The wire is wound up by the wire and travels in the direction shown by the arrow in the figure. The take-up reel 2 is driven by a take-up motor 3, and a rotation angle θ ₁ of the take-up motor 3 is detected by a rotation angle detector 4 and output as a rotation angle signal 10. On the other hand, the supply reel 5 is driven by the supply motor 6, and the rotation angle θ ₂ of the supply motor 5
is detected by the rotation angle detector 7 and output as a rotation angle signal 11. The drive currents of the take-up motor 3 and the supply motor 5 are supplied to the simulation circuit 12 as motor drive current signals 8 and 9, respectively.
The simulation circuit 12 simulates the dynamic characteristics of the motor using an electric circuit, calculates the rotation angles of both motors based on the input signals, and generates a simulated rotation angle signal 16 of the take-up motor 3 and a simulation of the supply motor 6. A rotation angle signal 17 is output, and a simulated tension signal 2 of the tape 1 is also output.
2. Calculate and output the simulated speed signal 23 of the tape 1. A configuration example and operation of the simulation circuit 12 will be described later.

Simulation rotation angle signal 1 outputted from the simulation circuit 12
6, 17 and the rotation angle signals 10, 11 are respectively detected by a rotation angle error detection circuit 13 and outputted as a rotation angle error signal 18. If the response of the simulation circuit 12 to the drive current is equal to the response to the actual drive current of both motors 3 and 6, the error detection signal 18 will of course be 0. However, in reality, it is difficult to completely represent the true response of the motor with a simulation circuit due to variations in motor torque, variations in solid friction, variations in inertia of rotating parts due to uneven tape thickness, etc. Therefore, the simulation circuit 12 uses the rotation angle error signal generated by these fluctuations.
An error correction signal for correcting the response of the signal is generated and fed back to the simulation circuit 12. The error multiplication circuit 14 receives the rotation angle error signal 18.
is multiplied by an error coefficient indicated by a simulating circuit corrected gain signal 20 outputted from a coefficient setting circuit 15, which will be described later, to output an error correction signal 19.
supply to. The rotation angle error detection circuit 13 and the error multiplication circuit 14 constitute an error correction circuit 24.
The above correction gain needs to be changed in response to changes in tape winding diameter and inertia due to tape transport, and is given from the coefficient setting circuit 15.

The coefficient setting circuit 15 is a circuit that receives the rotation angle signal 10 and generates the following coefficients required by the error multiplication circuit 14 and the simulation circuit 12 in accordance with changes in the inertia of the motor.

DC with the same characteristics for the take-up motor and supply motor
A motor is used, and the rotation angle θ ₁ , rotation speed ω ₁ , drive current i ₁ , rotating part inertia J ₁ , tape radius r ₁ on the take-up reel of the take-up motor, and similar parameters θ of the supply motor. ₂ , ω ₂ , i ₂ , J ₂ , r ₂ , the solid friction is ignored and the viscous friction coefficient is K _D ,
When the tape tension is T, the torque constant is K _T , and the tape spring constant is k, the driving currents of both motors are i ₁ , i ₂
The responses of the tape tension T, rotation angles θ ₁ , θ _{2 ,} etc. to the above are expressed by the following equation (1).

J ₁ θ¨ ₁ +r ₁ T=K _T i ₁ J ₂ θ¨ ₂ +K _D ω ₂ +r ₂ T=K _T i ₂ T〓=k(r ₁ θ〓 ₁ −r ₂ θ〓 ₂ ) (1) Rearranging the above equation (1), θ〓 ₁ =ω ₁ ω〓 ₁ =a ₁ ω ₁ +a ₂ T+b ₁ i ₁ θ〓 ₂ =ω ₂ ω ₂ =a ₃ ω ₂ +a ₄ Tb ₂ i ₂ T〓 =a ₅ ω ₁ +a ₆ ω ₂ (2). However, a ₁ = −K _D /J ₁ , a ₂ = −r ₁ /J ₁ ,
a ₃ = −K _D /J ₂ , a ₄ = r ₂ /J ₂ , a ₅ = kr ₁ , a ₆ = −kr ₂ ,
b ₁ = K _T /J ₁ and b ₂ = K _T /J ₂ . The above coefficient a ₁ ~
a ₆ , b ₁ , and b ₂ can be determined from the rotation angle signals 10 and 11 using a certain algorithm.

Also, the coefficients L ₁ to L ₁₀ are error correction gains,
For example, using the Kalman filter theory, it can be determined as follows. _Expression (2 ₎ can be written _as a state equation in vector representation as shown in equation (3) below _. =01000 0a ₁ 00a ₂ 00010 000a ₃ a ₄ 0a ₅ 0a ₆ 0 〓=00 b ₁ 0 00 0b _{2 00} , 〓=i ₁ i 2Observation when the actual observable state quantities are θ ₁ and θ ₂ If the value y is 〓=〓〓+〓 ……(4) However, 〓=θ ₁ θ ₂ , 〓=10000 00100 w=w ₁ w ₂ , where w is the observation noise, 〓=〓〓 ^T 〓 ^-1 ......(5) Calculated as:

However, 〓=E{(〓−E(〓))(〓−E(〓)) ^T ), and P is the root of the following differential equation.

〓＝〓〓＋〓〓 ^T ＋〓〓〓 ^T −〓〓 ^T 〓 ^-1 〓〓
...(6) However, 〓=E{(〓-E(〓)(〓-E(〓)) ^T } 〓=i ₁ i ₂ L is a matrix with 5 rows and 2 columns, and its elements are
_L1 to _L10 are used as coefficients. Furthermore, in the above
^-1 is the inverse matrix of 〓, 〓 ^T shows the matrix obtained by transposing 〓, and E(〓) shows the average of 〓.

The above-mentioned coefficients L ₁ to _{L 10} can be calculated using a fixed algorithm based on the winding amount (obtained from the rotation angle signal 10) if 〓 and 〓 are kept constant. If 〓, 〓 change, correspond to them.
It can be calculated from equations (5) and (6).

FIG. 2 is a block diagram showing an example of the configuration of the coefficient setting circuit 15. That is, motor rotation angle signal 1
A reversible counter 80 that counts 0 calculates the number of windings of the winding motor.
Coefficient storage memory 81, 8 by the output signal of 0
2, read out the coefficients L ₁ , L ₂ , . . . corresponding to the number of turns stored in advance. Coefficient L ₁ ~L ₁₀ , a ₁ ~
a ₆ , b ₁ , b _{2 ,} etc. can be determined using a certain algorithm from the number of tape turns using the Kalman filter theory, observer theory, and the proviso to equation (2), but in this example, they are determined in advance. By storing the coefficients determined corresponding to each number of windings in the form of a table in the coefficient storage memories 81, 82, . . . , the calculation time and the hardware amount of the calculation circuit are saved. The coefficient values read from the coefficient storage memory circuits 81, 82, . . . are converted into analog signals by digital-to-analog converters _{83 , 84,} . a ₆ , b ₁ ,
b ₂ and is supplied to the error multiplier circuit 14 and the simulation circuit 12. It is also possible to read the coefficients from the coefficient storage memory without counting the rotation angle signal 10 by the reversible counter 80, for example, by inputting a direct measurement result of the reel diameter as a digital value.

FIG. 3 is a block diagram showing a configuration example of the simulation circuit 12, the error detection circuit 13, and the error multiplication circuit 14.

The simulation circuit 12 is a circuit that electrically simulates the equation (2), and includes a multiplier 41 that multiplies the drive current signal 8 by a coefficient b ₁ and a multiplier 42 that multiplies the drive current signal 9 by a coefficient b ₂ . , an adder 43 which adds the output of the multiplier 41, the outputs of various multipliers to be described later, and an error correction signal 19 supplied from an error correction circuit and inputs the result to an integrator 30; and an adder 43 which integrates the output of the adder 43. an integrator 30, an adder 44 that adds the error correction signal 19 to the output of the integrator 30 and outputs the result, and an integrator 31 with reset that integrates the output of the adder 44 and outputs the simulated rotation angle signal 16; the integrator 30
a multiplier 48 which multiplies the output of the multiplier 42 by a coefficient C ₁ and outputs a simulated tape speed signal 23; an adder 45 which adds the output of the multiplier 42 to the outputs of various multipliers and an error correction signal 19, which will be described later. , adder 45
an integrator 32 that integrates the output of the integrator 32; an adder 46 that adds the error correction signal 19 to the output of the integrator 32;
A simulated rotation angle signal 1 is obtained by integrating the output of the adder 46.
7, a multiplier 40 that multiplies the output of the integrator 32 by a coefficient _a6 , and a multiplier 39 that multiplies the output of the integrator 30 by a coefficient _a5 .
and an adder 47 that adds the output of the multiplier 39, the output of the multiplier 40, and the error correction signal 19.
an integrator 34 that integrates the output of the adder 47 and outputs a simulated tape tension signal ₂₂ ;
a multiplier 36 that multiplies the output of the integrator 30 by a coefficient a ₁ and inputs it to the adder 43; a multiplier 35 that multiplies the output of the integrator 34 by a coefficient a ₄ and inputs it to the adder 45; It is composed of a multiplier 38 for inputting the signal, and a multiplier 37 for multiplying the output of the integrator 32 by a coefficient a ₃ and inputting the result to the adder 45. The coefficients multiplied by each of the multipliers described above are set by the output of the coefficient setting circuit 15.

The drive current signal 8 described above represents the drive current i ₁ of the winding motor, which is multiplied by b ₁ and integrated by the integrator 30 to obtain a simulated rotational angular velocity signal, which is integrated via the adder 44. When the rotation angle signal 16 of the simulated winding motor is integrated again by the device 31, it is obtained from the rotation angle signal 16 of the simulated winding motor. The multiplier 35 represents the viscous friction of the motor, and if this effect is small, the multiplier 35 may be omitted. In addition to this, the adder 43 includes a correction circuit 2.
The correction signal from adder 43 is inputted to adder 43.
The error of ω〓 ₁ (acceleration) in equation (2) is corrected by the output of (see the second equation (2)), and by configuring this, ω ₁ , that is, θ〓 ₁ (rotational speed) can be obtained. ((2) Equation 1
(see formula). The rotation speed θ〓 ₁ is multiplied by a coefficient C ₁ and output as a tape speed signal 23. The tape speed v is v=
Since r ₁ ω ₁ , the tape speed can be obtained by setting C ₁ =r ₁ . The rotation angle θ ₁ is obtained by integrating θ〓 ₁ . In addition to the output of the integrator 30, the error correction signal 19 from the correction circuit is input to the adder 44, and a corrected speed signal is obtained at the output of the adder 44. Then, a rotation angle signal obtained by integrating the output of the adder 44, that is, a simulated winding motor rotation angle signal 16 is output to the error correction circuit 24.

The adder 45, integrator 32, adder 46, and integrator 33 calculate the simulated rotation angle of the supply motor in the same manner as described above, and send it to the error correction circuit 24 (see equations 3 and 4 in (2)). . Also, a signal obtained by multiplying the output of the integrator 32 by a coefficient a ₆ and a signal obtained by multiplying the output of the integrator 30 by a coefficient a ₅
The differential value of the tension is created by adding the error correction signal 19 from the correction circuit to the sum of the multiplied signals (see the fifth equation of equation (2)), and this is integrated by the integrator 34 to obtain the simulated tape tension. It is issued as signal 22. With the above-described configuration and operation, the response of the simulation circuit can be brought close to the response of the real motor, so it is possible to output a tape tension signal proportional to the rotation angle difference between the two motors with high precision.

The above configurations differ in the way the dynamic characteristics of the two motors are expressed. For example, when the viscous friction of the motor is small, the multipliers 35 and 37 may be omitted. Furthermore, if the solid friction between the tape and the motor cannot be ignored, a signal corresponding to the solid friction may be additionally supplied to the adders 43 and 45.
Various other abbreviations are possible.

FIG. 4 is a circuit diagram showing an example of the configuration of the integrators 31 and 33. That is, a parallel circuit of a capacitor and a switch 70 is connected between the output of the operational amplifier 71 and the -input terminal, and the switch 70 receives the reset signal 74.
Controlled on and off by When switch 70 is on, the charge on the integrator capacitor is reset to zero, and the integrator output signal 73 becomes zero. When the switch 70 is turned off, a normal integration operation is started, and an output signal 73 obtained by integrating the input signal 72 is output. This reset function prevents the rotation angle signal from becoming saturated even if the motor continuously rotates in the same direction. The reset signal 74 is given, for example, at regular intervals.

FIG. 5 is a block diagram showing an example of the configuration of the subtracter 50 of the error detection circuit 13 shown in FIG. That is, pulse signals having a phase difference of 90° from each other are output from a rotation angle detector attached to the winding motor and inputted as a rotation angle signal 10. When one pulse of the above pulse signal is inputted to the data input D of the D-type flip-flop 90 and the other pulse is inputted to the clock input c, a signal indicating the rotational direction of the motor is outputted from the output terminal Q. This signal specifies up or down count operation of the reversible counter 91. The reversible counter 91 up-counts or down-counts one of the pulse signals input to the clock input, and supplies the count value to the digital-to-analog converter 92. The digital-to-analog converter 92 converts the input signal into an analog signal a and outputs it. Since the counter 91 is reset when it reaches a certain count value or by a pulse (not shown) of a certain period, the analog signal a becomes a sawtooth wave as shown in FIG. 6a. On the other hand, the simulated rotation angle signal 16 supplied from the simulation circuit 12 has a waveform as shown in FIG. By adding the signal 16 and the signal a using an operational amplifier 93, an error signal c as shown in c in the figure is obtained. The error signal c
Since d becomes 0 at each reset, the control signal 95 causes the sample and hold circuit 94 to hold the error signal immediately before the reset, and the held signal d
(see FIG. 6d) is again added to the input of the operational amplifier 93, so that a continuous error signal c' as shown in FIG. 6e is outputted as the rotation angle error signal 18. The same applies to the subtracter 51 in FIG.

As shown in FIG. 3, the error multiplication circuit 14 inputs the rotation angle error signal 18 of both motors output from the error detection circuit 13, multiplies the input signal by coefficients _L1 to _L10 , and corrects the error of the multiplication result. Each of the signals is supplied as a signal 19 to each part of the simulation circuit 12. This modifies the response of the simulation circuit 12 so that it nearly matches the response of the actual motor. As a result, the simulated tape tension and tape speed approach the true tape tension and tape speed and are output with high accuracy. Note that the coefficients L ₁ to _{L 10} are given from the coefficient setting circuit 15.

Therefore, the simulation circuit 12 uses an error correction signal obtained by multiplying the error between the simulated rotation angle signal calculated by a certain algorithm based on the drive current signals of both motors and the actual rotation angle signal by a coefficient. While being corrected, simulated tape status signals such as tape speed signals and tension signals are output. That is,
The simulated tape status signal has the effect of quickly outputting an accurate tape status. Since tension arms and friction rollers are not used, they do not cause vibrations to the tape.
It does not provide any resistance to tape running, and it is possible to react sufficiently quickly even at high acceleration times such as starting and stopping tape running. Moreover, even if the output of the motor state detection section contains a lot of noise, it is possible to output a simulated motor state signal and tape state signal with less noise.

The above is an example in which the motor state detection section is configured by the rotation angle detector 4, but by using a rotation speed detector as the motor state detection section, for example, the cost of the detection device can be reduced, and the motor can be reduced in price. Inertia is possible. In this case, the simulation circuit includes a simulation circuit that outputs a simulated rotational speed signal of the motor, and it goes without saying that the difference between the actual rotational speed signal of the motor and the simulated rotational speed signal is detected as an error. Furthermore, for example, the motor state detection section can be configured by a rotation angle detector that detects the rotation angle of the take-up motor and a rotation speed detector that detects the rotation speed of the supply motor. In this case, of course, errors related to the rotation angle of the take-up motor and errors related to the rotation speed of the supply motor need to be detected by error detection circuits.

As described above, in the present invention, based on the drive current signals of the winding motor and the supply motor,
Since it is configured to detect tape conditions such as tape speed and tape tension using an electrical simulation circuit, it is possible to quickly detect tape conditions without contacting the tape, such as during high acceleration such as starting and stopping. Also, there is an effect that a highly accurate output signal can be obtained. This is advantageous in achieving high speed and high precision tape tension control and tape feed control. Furthermore, since the rotational speed of both motors can be obtained in the process of detecting the state of the tape, it can also be used as a stabilizing signal for the tension control loop and the tape feed control loop. In addition, since there is no mechanical part such as a tension arm for detection, there is no negative effect on the tape due to vibrations, etc., and it is small, inexpensive, high speed, and high precision direct tape feeding between reels. It becomes possible to realize the device. Note that the present invention is not limited to magnetic tapes, and can be widely applied to the field of conveying not only paper tapes, films, etc., but also linear flexible bodies such as electric wires, optical fibers, wires, and threads. Yes, it has a wide range of applications.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
FIG. 2 is a block diagram showing an example of the configuration of the coefficient setting circuit of the above embodiment, FIG. 3 is a block diagram showing an example of the structure of the error detection circuit, error multiplier circuit, and simulation circuit of the above embodiment. Integrator 3 shown in Figure 3
5 is a block diagram showing a detailed construction example of the error detection circuit of the above embodiment, and FIG. 6 is a time chart showing signals of various parts of the error detection circuit. In the figure, 1...magnetic tape, 2...take-up reel, 3...take-up motor, 4, 7...rotation angle detection signal, 5...supply reel, 6...supply motor, 8, 9...
Motor drive current signal, 10, 11... Motor rotation angle signal, 12... Simulation circuit, 13... Error detection circuit, 1
4...Error multiplication circuit, 15...Coefficient setting circuit, 16,
17... Simulated rotation angle signal of the motor, 18... Error signal, 19... Error correction signal, 20... Correction gain (coefficient) signal, 21... Coefficient signal, 22... Simulated tape tension signal, 23... Simulated tape speed signal , 24...
Error correction circuit, 30-34... Integrator, 35-4
2, 48, 52-61... Multiplier, 43-47... Adder, 50, 51... Subtractor, 70... Switch, 7
1... Operational amplifier, 72... Integrator input signal, 73
...Integrator output signal, 74...Reset signal, 80
...Reversible counter, 81, 82...Coefficient storage memory,
83, 84...Digital analog converter, 90...D
Type flip-flop, 91... Reversible counter, 92...
Digital-to-analog converter, 93...Operation amplifier, 9
4...Sample hold circuit, 95...Control signal.

Claims (1)

[Scope of Claims] 1. In an inter-reel direct tape feeding device comprising a take-up motor that drives a take-up reel and a supply motor that drives a supply reel, the drive current of the take-up motor and the drive current of the supply motor are a simulation circuit that simulates and calculates and outputs the states of the two motors and tape states such as tape tension and tape speed using an electric circuit based on the above; a motor state detection section that detects the states of the two motors; an error detection circuit that detects the difference between the motor status signal outputted by the section and the motor simulation status signal outputted from the simulation circuit; and an error that multiplies the output of the error detection circuit by a coefficient outputted from the coefficient setting circuit described later. a multiplier circuit, and a coefficient setting circuit that calculates the amount of tape transfer based on the output of the motor state detection section, calculates the inertia and tape winding diameter of both motors, and creates and outputs various coefficients necessary for the operation of the error multiplier circuit and the simulation circuit. A tape condition signal detection device comprising: an output of the error multiplier circuit is inputted to the simulation circuit as an error correction signal, and the simulation circuit performs a correction operation based on the error correction signal. 2. In the tape condition signal detecting device according to claim 1, the motor condition detecting section includes a rotation angle detector that detects a rotation angle of the motor,
The simulation circuit includes a circuit that simulates a rotation angle signal, and the error detection circuit detects a difference between the rotation angle signal output from the rotation angle detector and the simulated rotation angle signal output from the simulation circuit. What to do. 3. In the tape condition signal detecting device according to claim 1, the motor condition detecting section includes a rotation speed detector attached to a motor, and the error detection circuit detects the rotation output from the rotation speed detector. The apparatus is characterized in that a difference between a speed signal and a simulated rotational speed signal outputted from the simulation circuit is detected. 4. In the tape condition signal detection device according to claim 1, the motor condition detection section includes a rotation angle detector that detects the rotation angle of the take-up motor and a rotation speed detector that detects the rotation speed of the supply motor. The error detection circuit detects a difference between the output of the rotation angle detector and the rotation speed detector, and a corresponding simulated output signal of the simulation circuit, respectively.