JPS581204A - Antibacklash driving device for rotating body - Google Patents

Abstract

PURPOSE:To simplify the circuit and to improve the reliability of failure detection, by obtaining current difference flowing to the 1st and 2nd motor and deenergizing both the motors when the difference is greater than a reference value. CONSTITUTION:Currents IM1 and IM2 flowing to motors 4 and 5 are inputted to an adder 23, the difference is outputted and compared with a reference value (c) at a comparator 24. When a driving circuit 1 is normal, the difference of torque of the motors 4 and 5 is 2Tp, the output of the comparator 24 is turned off, and a relay 20 is inoperative. When the torque difference is 2Tp or more, the output of the comparator 24 turns on a switching transistor 19, a relay 20 is operated , its contacts 20a and 20b are opened and the motors 4 and 5 are turned off. Thus, a failure detection circuit 21 detects a failure of the circuit 1, and if an excessive load is applied to a gear of the circuit 1, the motors 4 and 5 are turned off to prevent the damage. Thus, a complicated simulated load circuit is unnecessary, the circuitry is made simpler and the reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-backlash drive device for a span rolling element, which is equipped with an abnormality detection circuit that detects the occurrence of an abnormality in a drive assist circuit and turns off the drive circuit.

A conventional device of this type is shown in FIG.

In the figure, % (1) is a drive circuit for anti-backlash driving the antenna, and (2) is this drive circuit (1).
This is an abnormality detection circuit that detects an abnormality when it occurs and turns off the drive circuit (1). In the drive circuit (1), the +31h antenna (which can be seen as the load of the 31Fi drive circuit (1).14) +51 outputs counterclockwise and clockwise torques to The first step is to drive the antenna (3) with anti-backlash. The second motor s+63(7) detects the rotational speed of the motor 14+15) and the second motor s+63(7) detects the rotational speed of the motor 14+15). A tacho generator generates the second speed feedback signals fs and fg, a is a speed command signal, and (8) is the first speed feedback signal. (9) is an adder (
8) an amplifier that amplifies the speed error signal C which is the output of (
(to) (company) is an adder that adds the output of amplifier 19) and DC bias +VB, VB, respectively. A speed control circuit (2) is configured as a motor drive circuit that drives the ts1 rotation. 11:l (14 is configured with a speed control circuit. 1314) amplifies the speed control signal that is the output of the speed control circuit σ2, and transmits it to the relay (to) described later.
This is an amplifier that applies voltage to the first and second motors 14 +51 through the contacts (20b).

In the abnormality detection circuit (2), +15 is a speed control circuit configured similarly to the speed control circuit (2) of the drive circuit (1), and ue is a speed control circuit that is electrically equivalent to the load of the drive circuit (1). Pseudo load circuit, surface is the above tacho generator 16)
1st from +7). An adder that adds the second speed feedback signal gf+, a signal obtained by multiplying tg by 1/2, u8 is an adder αη
a comparator, dl, that compares the difference between the output of
is a switching transistor; 1. aFi The relay that turns off the first and second motors (4) + 5), the fault is from the transistor uI and the relay (to), and when the output of the comparator ul is high, the 11th second motor t41 +5) This is a switching circuit that turns off the

I will explain the next KtIh work.

First, in the drive circuit (1), when the antenna (3) is not rotating and the speed command signal a is 'Ol', the speed error signal e is also '0', and the direct current
-V1a cuckoo'! 1M51, $20Mo1
Ninth, both motors added to +41+51 (41+5
), t/L/97P, -re is added to the reflection force, and both torques cancel each other out, so the antenna (3) does not rotate and the motor t4) +51 also does not rotate. In this situation, when a positive speed command signal a is applied, the speed feedback signal ti from the tacho generator +6) +71 is
', so the speed command signal a. becomes the speed error signal 9C as it is, is amplified by the amplifier (9), and is applied to the adder uI 111 K#, and the DC bias +V!
l, -Vm are added. As a result the first motor (4)
has a signal chi of +(Vyr+λ0), and the second motor (
5) is applied with a signal force f of -(VB-jig), and as a result, as shown in FIG.
The output torque of 4) is Tp 10ra, and the output torque of the second motor (5)
The output torque of is -('I'P-Tl.), and the counterclockwise torque of the first motor (4) is larger than the clockwise torque of the second motor (5). t4
) +51 #-1, respectively rotate counterclockwise and rotate the antenna (3) clockwise. As a result, the rotational speed of the antenna (3) increases to reach the above command value. However, to be more precise, since there is a frictional torque of the motor 14) 15) and the antenna (3) which is the load, the antenna (3)
) has a rotational speed of 3'.

So, Δa=a0-a'. is the speed corresponding to the friction torque of the motor and load. Therefore motor f4115
1) Luku TP+△r ("F-A゛r) Torque"'C7nf f (3) is velocity breath'. It will continue to rotate.

On the other hand, in the abnormality detection circuit (2), the speed control circuit +1
! il operates in the same manner as the speed control circuit u2 of the drive circuit tl) according to the speed feedback signal island, and outputs the pseudo load circuit tl.
When the antenna (3) is being driven normally, the pseudo load speed signal from the pseudo load circuit Oe is equal to the speed feedback signal f+, ft from the tacho generator +61 +7). , Therefore, the difference between the output of the adder and the above pseudo load speed signal is Vi% o I, which is the output Fi of the comparison mus, so the relay (
to) does not work. By the way, the antenna (3) may have hit an obstacle and cannot rotate), or the tachogenerator +61 or +71 may have malfunctioned.
If the motor 141 +6) is stopped forcibly or the tachogenerator 16) +71
is the feedback signal fl, f! whose speed is different from the actual rotational speed of the motor t41.51. As a result, a difference occurs between the output of the adder αη, which is the average of the speed feedback signal f5ft, and the pseudo load speed signal S. If the difference becomes large, there is a risk that an abnormal load will be applied to the mechanical components of the drive circuit (1) and they will be damaged. However, if the value of the difference becomes larger than a certain reference value C, the output of the comparison 1Btll will be / ~ becomes a transistor tl
l is turned on, the relay (to) is operated, and its contact (20a
) (20b) is turned off and the first and second motors 141
151 #i is turned off, and in this way, the abnormality detection circuit +21 can prevent damage to the mechanical components of the drive circuit (1). Note that the second cause A is antino f
Shows the crash area.

Anti-backlash of conventional antenna, 1M, 11
The device is configured as described above, and includes an abnormality detection circuit +
21 d The occurrence of an abnormality is detected by comparing the output of the pseudo load circuit (2) with the average of the outputs of the tacho generator + and 11 (7), but the pseudo load that magnetically simulates the load Circuit (II) Since the load is actually mechanical, the circuit configuration would be extremely complicated to make its characteristics such as natural vibration almost the same as the load, and it would be difficult to make the two have exactly the same characteristics. Since it is impossible to do so, the response speed of the load and the pseudo load are different, and the reliability of the abnormality detection of the abnormality detection circuit (2) inevitably decreases to some extent. Furthermore, the pseudo load circuit tII has a complicated configuration and is prone to failure, and when a failure occurs, the first and second motors (
41(5) is turned off, and this also has the disadvantage of reducing the reliability of abnormality detection.

By the way, in the antenna anti-backlash drive device shown in Fig. 1, when the antenna is being driven normally, the difference in the output torque of the two motors is always 2TP as shown in Fig. 2. , TPO torque is applied to the tooth surface of the gear on the load shaft. Therefore, under normal conditions, the strength of the tooth surface only needs to be designed to withstand TP and acceleration torque. However, if a failure occurs in the drive circuit, the torque difference between the motors will often exceed 2 TP, and if this happens, a load force (more than the design value) will be applied to the gear, which may cause damage to the gear. By detecting the torque difference between the two, damage to the gear due to a failure of the drive circuit can be prevented.

This invention was made by focusing on the torque difference between the two motors as described above in order to eliminate the drawbacks of the conventional motors as described above. By determining the current difference between the two motors using the current difference and turning off the first and second motors when the current difference becomes larger than the reference value, the dummy load circuit can be created by turning off the first and second motors to prevent damage to the gear. It is an object of the present invention to provide a crush drive device for a rotating body, which simplifies the circuit by eliminating the need for a rotor and improves the reliability of abnormality detection.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows an anti-backlash driving device for an antenna according to an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 1 indicate the same components as in FIG. 1, and (2) is an abnormality detection circuit of the present device. In this abnormality detection circuit (2),
One end of ILl and R1 are connected to the first and second motors t41 i5
A resistor connected to the terminal of armature 1 and whose other end is grounded,
@ is an inverting amplifier that inverts the polarity of the current hl extracted from the second motor (5) by the resistor R1, and (c) is the current IMI extracted from the first motor (4) by the resistor R1. and the output of the inverting amplifier @-IM! (To) is a comparator that compares the output (IMI-IM) of the adder (To) with the reference signal C, and the reference value C is the current corresponding to the torque difference 2TP of the motor +41151. value 2
It is set to a slightly larger value (IF to 21P+) than 1F.

Next, I will explain the previous work.

The drive circuit (1) of this device is the same as the conventional one shown in Fig. 1, and the antenna (3) is connected to the first and second motors t4.
+ Anti-backlash driven by +51.

At that time, 1. The current IMI, IMg flowing through the second motor f41 +51 is the current in the opposite direction in anti-backlash head A, that is, when IMI is positive, IMg
is negative, but the current IMR of the second motor (5)
is inverted by the inverting amplifier and then input to the adder,
The output of this adder (to) contains both currents IMI, the current difference between both motors lal +51 equal to the sum of the absolute values of 1Mg (
IMI-IMffi) is obtained. This output is compared with the reference value C in the comparator (to), but if the drive circuit (1) is operating normally, both motors +41
The torque difference Fi2TP is +51, so the 4-flow difference between both motors +41151 (IMI - 1mg) d) is equal to 21F, which corresponds to the torque difference 2TP, so the comparator (
) is off, switching transistor u
11 does not turn on, and relay ■ does not operate. On the other hand, if a failure occurs in the drive circuit () and the torque difference between both motors f41 +51 becomes 2TP or more, one motor +4) t5
) is more than (21P+ΔIF), so the output of the comparator (to) turns on transistor ttS, activates relay 1, and its contacts (20m) (20b) The first and second motors t41 to t5) are immediately turned off. In this way, the abnormality detection circuit (2) detects a failure of the drive circuit txt,
If an excessive load is applied to the mechanical components such as gears of the dedicated circuit (1), the first and second motors (41+5
1 can be turned off to prevent damage such as leakage.

In the antenna anti-backlash drive IIJ device of this embodiment as described above, the abnormality detection circuit @ detects the current difference (l old -1 w, 1), there is no need to provide a complicated dummy load circuit like in the past, and the @path configuration of the abnormality detection circuit 1iiiIJ is simplified.As a result, the four normal detection circuits ( The possibility of a failure occurring in the company) is reduced, and the reliability of abnormality detection is greatly improved.

Although the above embodiment has been described with reference to an anti-backlash drive device for an antenna, the present invention can be similarly applied to anti-backlash drive devices for other rotating bodies.

As described above, according to the anti-backlash drive device for a rotating body according to the present invention, the first. The current flowing through the second motor is collected to find the four-current difference between both motors, and when it becomes larger than the reference value, the first and second motors are turned off to prevent damage to the drive circuit. As a result, the configuration of the abnormality detection circuit can be simplified by eliminating the pseudo load circuit, and the reliability of abnormality detection can be improved by reducing the occurrence of failures in the abnormality detection circuit. .

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional antenna anti-backlash drive device, FIG. 2 is a diagram showing the characteristics of motor output torque with respect to a speed error signal in the above device, and FIG. 3 is an antenna according to an embodiment of the present invention. 1 is a schematic configuration diagram of an anti-backlash drive device of FIG. (3)...Antenna (rotating body), +41 +61...
・Motor, --- Speed control circuit (motor drive circuit)
, 1... Adder (operating unit), (To) - Comparator, (To)... Switching circuit.

Claims (1)

[Claims] 1.) A rotating body and a first element for anti-backlash driving the rotating body. a second motor; a motor drive circuit that rotationally drives a second motor; a calculation unit that calculates the difference between the current value flowing through the first motor and the current value flowing through the second motor; a comparator that compares the signal with a reference signal; and when a signal is output from the comparator indicating that the output of the arithmetic unit is larger than the reference signal, the first 1. An anti-backlash drive device for a rotating body, comprising: a switching circuit for turning off a second motor.