JPS6055023B2 - automatic balancing instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-balancing instrument utilizing a novel position feedback means.

Potentiometers using sliding resistors are widely used as position feedback means in conventionally known self-balancing instruments.

However, since sliding resistors have mechanical contact parts, there are various problems with long-term use, such as wear resistance, dust resistance, and environmental resistance.

The present invention aims to solve these problems all at once and realize a highly reliable self-balancing instrument.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, 1 is a pointer which is a movable part, and 2 is a wire for moving this pointer 1. In the present invention, a magnetostrictive wire, such as Ni-SPANC) nickel, is particularly used for this wire. The attachment portion of the wire 2 made of this magnetostrictive wire to the pointer 1 is treated so that the ultrasonic signal generated within the magnetostrictive wire 1 is reflected at this portion. 31, 32, 33
is a pulley for the wire 2, and the wire is suspended so that the ultrasonic signal propagating within the wire 2 is not reflected at this part.

41 and 42 are on both sides of the pointer 1, and pulleys 31 and 32
Excitation means 51, 52 are coupled to the wire 2 made of magnetostrictive wires in the vicinity and generate ultrasonic signals in the magnetostrictive wires; This is a receiving means for receiving the reflected ultrasonic signal reflected from the attachment part of the pointer 1.

The excitation means 41 and 42 and the reception means 51 and 52 may be used as one means. 05 is an excitation pulse generator, and its output pulse PE is applied to excitation means 41 and 42 as well as a flip-flop circuit FFI, which will be described later.
It is applied to the set terminal S of FF2.

0P1 and 0P2 are both comparator amplifiers that identify the pulse signal caused by the reflected ultrasonic signal reflected from the attachment part of the pointer 1, amplify it, and send it to flip-flop circuits FFl and F.
Apply to reset terminal R of F2.

CK is an arithmetic circuit that receives time width signals PWl and PW2 obtained from flip-flop circuits FFl and FF2. The output signal E of the arithmetic circuit CK becomes a position feedback signal for the pointer 1, which is a movable part, and is matched with the input signal Ei to drive the balance motor BM so that Ei=Er. The rotating shaft of the balance motor BM is connected to a pulley 33, and moves the pointer 1 in the direction of the arrow via the wire 2. The operation of the apparatus constructed in this way will now be explained with reference to FIG.

First, an excitation pulse PE is simultaneously applied from the excitation pulse generator OS to the excitation means 41 and 42 as shown in FIG. 2A. When an excitation pulse is applied to the excitation means 41 and 42, an ultrasonic signal is generated inside the wire 2 made of magnetostrictive wire due to the so-called Joule effect, which is directed toward the pointer 1 side and the pulley side. and propagate. The ultrasonic signal propagating toward the pointer 1 side is reflected at the attachment part to the pointer 1, and the reflected ultrasonic signal is transmitted to the first receiving means 51 and the second receiving means 52, as shown in Figure 2 and C, respectively. detected. The ultrasonic signal propagating toward the pulley is attenuated at the pulley. Now, the excitation pulse PO is applied to the excitation means 41.
, 42, an ultrasonic signal is generated within the wire 2 at the same time as the ultrasonic wave generated from the excitation means. The time T2 from when the signal is reflected at the attachment part of the pointer 1 until it is detected by the receiving means can be expressed by equations (1) and (2).

However, Vs: Ultrasonic signal propagates within wire 2
d: Distance between the excitation means and the receiving means (constant value) e1: Distance between the receiving means 51 and the attachment part of the pointer 1 (variable depending on the position of the pointer 1) E2: Distance between the receiving means 52 and the pointer 1 Mounting part
The excitation pulse PE (variable depending on the position of the pointer 1) is applied to the excitation means 41 and 42 and simultaneously applied to the set terminals s of the flip-flop circuits FFl and FF2. The circuits FFl and FF2 are set to the set state as shown in FIG. 2 2 and E.

Further, after Tl, t2 after applying the excitation pulse PE, pulsed signals El and e2 obtained from the first receiving means 51 and the second receiving means 52 (see Figure 2, Figure 2) are sent to the flip-flop. The voltage is applied to the reset terminals R of the circuits FFl and FF2, respectively, to put them in the reset state as shown in FIG. Therefore, the flip-flop circuit F
From the output terminals of Fl and FF2, time width signals PWl and PW2 having time widths Tl and t2 proportional to El and e2 are obtained as shown in FIG. 2, 2 and E, respectively. The arithmetic circuit CK has a time width Tl from each flip-flop circuit FFl, FF2,
By detecting t2 and calculating equation (3), a position feedback signal Ef related to the displacement position x of the hand 1 is obtained.

However, since X='1-E2 (3), d+e1+E2 is a constant value regardless of the displacement position x of the pointer 1, the feedback signal E is exactly proportional to the displacement position x.

The feedback signal E, related to the displacement position of the pointer 1, which is the movable part, obtained in this way is not affected by the propagation velocity Vs of the ultrasonic signal and can be obtained without using any mechanical contact part. It has characteristics.

Another feature is that there is no need to connect the movable part and the electric circuit with lead wires or the like. This feedback signal E,
is compared with the input signal e[, and the balanced motor BM has Ei=
Move the pointer 1 so that it becomes E, and automatically equilibrate there. Therefore, the pointer 1 can be made to accurately follow the input signal E, and the magnitude of the input signal el can be determined from the displacement position of the pointer 1. Note that the arithmetic circuit CK may perform an arithmetic operation as shown in equation (4).

In this case, since the feedback signal E, is affected by the propagation velocity Vs of the ultrasonic signal, the wire 2 is made of a material whose propagation velocity Vs does not change much due to temperature etc., such as Ni-SPANC.
It is desirable to use ▼S In the above embodiment, the excitation means and the reception means are set according to the guideline 1.
e1 is placed on both sides of the pointer 1 to obtain two types of time width signals related to the position of the pointer 1, and these are calculated. Alternatively, one time width signal related to E2 may be obtained.

Further, although the flip-flop circuit is set by the excitation pulse PE from the excitation pulse generator G, the ultrasonic signal propagating toward the pointer 1 is detected by the receiving means 51, It may also be set using this signal. In this case, the time width is .
Vs As explained above, according to the present invention, the entire structure can be made without any mechanical contact parts, and there is no need to connect the movable part and the electric circuit with lead wires, etc., so that problems with conventional devices can be avoided. A highly reliable self-balancing instrument that solves all problems at once can be realized.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention, and FIG.
The figure is an operational waveform diagram of the apparatus shown in FIG. 1... Pointer (movable part), 2... Wire, 31-33
:...Pulley, 41, 42...Excitation means, 51, 5
2...Receiving means, G...Excitation pulse generator, FFL
, FF2...Flip-flop circuit, CK...Arithmetic circuit, BM...Balanced motor.

Claims (1)

[Scope of Claims] 1. A movable part, a wire treated so that an ultrasonic signal is reflected at an attachment part to the movable part made of a magnetostrictive material, and a balanced electric motor that drives the pointer via this wire; an excitation means coupled to the wire and generating an ultrasonic signal within the wire; a receiving means coupled to the wire and receiving a reflected ultrasonic signal reflected at a mounting portion of the movable part; and an ultrasonic signal generated within the wire. circuit means for obtaining a signal corresponding to the movement of the movable part using a signal related to the time required for the motor to travel back and forth between the receiving means and the attachment to the movable part; An automatic balancing instrument that drives the movable part so that a signal and a signal corresponding to the position of the movable part are equal. 2. An excitation means and a receiving means coupled to the wire are provided on both sides of the movable part, and 2 2. The automatic balancing instrument according to claim 1, wherein a signal corresponding to the movement of the movable part is obtained by obtaining two types of signals and calculating these two types of signals.