JPH07100599B2 - Balance cargo handling device control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an actuator for raising and lowering a work, a drive circuit for driving the actuator, a force detector for detecting the weight of the work, and an operator for issuing a speed command. Equipped with a speed commander to input and a calculation circuit that calculates the output to the drive circuit based on the detected work weight and speed command, and the actuator outputs the force corresponding to the weight for an arbitrary heavy work The present invention relates to a control circuit of a balanced cargo handling apparatus which realizes a balanced state and allows a person to directly touch a work to move up and down with a light force.

[Conventional technology]

 The present applicant previously applied for the balanced cargo handling device shown in FIG.

That is, the rope 3 is wound around the drum 2 which is rotated by the motor 1 as an actuator, and the work 7 is suspended on the rope 3 via the speed commander 4, the acceleration detector 5, and the force detector 6. A speed detector 8 for detecting the rotation speed of the motor, a position detector 9 for detecting the rotational position of the motor 1, and an arithmetic circuit 10 are provided, and the arithmetic circuit 10 includes a lever mode arithmetic unit 11, a position mode arithmetic unit 12, and a balance. A mode operation unit 13, a balance stationary mode operation unit 14, a weight storage unit 15, and a mode selection unit 16 are provided, and one of the mode operation units is selected by this mode selection unit 16 to output a control signal to the drive circuit 17. The holding force of the motor 1 commensurate with the weight of the work 7 can be applied to balance the work, and the lever 4a
When the command speed is input, the motor 1 is rotationally controlled so as to match the command speed, and a person can move the work 7 up and down with a light force.

Specifically, the speed command device 4 outputs a speed command signal R according to the operation amount of the lever 4a, and the force detector 6 detects a load (force) acting on the work 7. and outputs the signal F _L Te. Further, the position detector 9 outputs a rotational position signal x of the motor 1, and the speed detector 8 outputs a speed signal V.

The drive circuit 17 is composed of an adder 18 that takes the deviation between the command value Vf and the speed signal V of the motor 1 and a drive unit 19, and drives the motor 1 in accordance with the deviation Vf-v.

20 is a motor acceleration feedback circuit, which is a motor 1
Differentiator 21 for differentiating the speed signal V output from the speed detector 9 to obtain the acceleration signal of the motor 1 and an addition point 22. From the acceleration signal at the addition point 22 and the arithmetic circuit 10 described later. The speed command value V _M is fed back to output the command value Vf.

The weight storage calculator 15 stores the weight W of the work 7 and outputs a weight command W ₀ .

Next, the operation will be described.

(1) Lever mode First, the lever 4a of the speed command device 4 is operated. Speed commander 4
The speed command signal R output from is input to the lever mode operation unit 11 of the operation circuit 10. On the other hand, for stabilization, the speed signal V is also input from the speed detector 8 to the lever mode calculation unit 11.

The lever mode calculation unit multiplies the gain, and the result is input to the drive circuit 17 of the motor 1. At this time, the motor 1
The speed signal V is multiplied by the gain Kvn, is negatively fed back (negative feedback), is input to the drive circuit 17, and the command value Vf is stabilized.

The lever mode has priority over other modes, and if there is a lever input, the mode selection circuit 16 is forced to switch to the lever mode position.

(2) Position mode In the position mode, the mode selection circuit 16 starts the position mode position immediately after the lever 4a stops and the speed command signal R by the lever 4a disappears, that is, when | R | <threshold R _0. It is switched to and started. At the same time, the load memory calculation unit 15 also starts to operate. After the position mode start, if even storage time T _M is too worker be operated | weight signal F _L - stored value W ₀ | position mode becomes ≦ threshold F ₀ is maintained.

If the accuracy of the weight storage value W ₀ is within the threshold value F ₀ , the balance mode is not moved and the position mode is maintained and still. The threshold value K ₀ and the threshold value F ₀ are preset.

In the position mode, position feedback is applied to make the work 7 stand still, and in actuality, the deviation x−x ₀ from the motor position signal X at the moment when the position mode is entered is multiplied by a gain to perform negative feedback. On the other hand, for stabilization, the motor speed signal V
Is multiplied by the gain to give negative feedback.

(3) Balance mode The mode shifts after the time T _M after the mode becomes the position mode, and when the absolute value | F _L −W ₀ | of the operating force acting on the work 7 becomes larger than the threshold F ₀ .

The detected value F _L from the force detector 6 is compared with the weight command W ₀ from the weight storage operation unit 15 at the summing point 23 as in the fourth diagram, the deviation (W ₀ -F _L) to a predetermined It is multiplied by the gain K _F. Further, for stabilization, the motor speed signal V is multiplied by the gain Kvp to perform positive feedback, and the result is input from the mode selection circuit 16 to the adder 22 of the acceleration feedback circuit 20.

The weight storage calculation unit 15 has a work 7 when stationary.
Is stored in advance.

If the worker applies an upward operation force (load) F to the work 7 that is still now, the force detector 6 at this time
The detected value _{FL of} is input to the addition point 23. Summing point 23 is compared with the output W ₀ and the detected value F _L from the weight storage operation unit 15.

Then, the deviation is multiplied by the force feedback gain K _F and amplified. The operating force signal at this time is positively fed back to a value obtained by multiplying the motor speed signal V by the speed positive feedback gain Kvp, and then input to the acceleration feedback circuit 20. In this case, the force detector 6 is operated by the upward operation force F.
Since the detected value F _{L of} is decreased, the deviation that the addition point 23 is output
W ₀ − (W−F) is the operating force F compared to the deviation W ₀ −W at rest.
The motor torque is increased by this and the work 7
Moves upwards. That is, when the force detector 6 senses the operating force F when the force is applied to the work from the equilibrium state, a deviation for moving the work 7 up and down occurs at the addition point 23, and therefore the force feedback gain K _F is increased. If it is made large enough, the worker will not feel any static friction, and the work 7
Can be raised and lowered.

[Problems to be Solved by the Invention]

With such a control circuit, when the worker applies a force to the work 7 in order to move the work 7 up and down from the equilibrium state, the force detector 6 detects the applied force, that is, the operating force, and the detected value _FL And the difference W ₀ −F _L between the weight storage value W ₀ and
A value obtained by multiplying the deviation W ₀ −F _L by the force feedback gain K _F and the speed signal V by the speed positive feedback gain Kv
Since the values multiplied by p are added to obtain the speed command value V _M , the magnitudes of the respective gains K _F and Kvp are important.

That is, if the gains K _F and Kvp are increased, the operation force when moving the work 7 at high speed can be reduced, but on the other hand, the operation force when moving the work 7 at low speed becomes too light and only a little force is applied. As a result, the work 7 largely moves and the positioning performance deteriorates.

Therefore, it is an object of the present invention to provide a control circuit for a balanced cargo handling apparatus that can reduce the operating force when moving at high speed and can improve the positioning performance when moving at low speed.

[Means and Actions for Solving the Problems]

The actuator that moves up and down the workpiece, the drive circuit that drives the actuator, the speed commander that the operator inputs the speed command, the force detector that detects the load, the speed detector that detects the actuator speed, and the actuator position Output the input signal to the actuator drive circuit based on the position detector to detect and the detection signal of each detector,
An arithmetic circuit for storing the weight of the work, to the arithmetic circuit, the force detector of the force detection signal F _L and the weight stored value
A value to the deviation W ₀ -F _L multiplied by the force feedback gain K _F and W _0, the calculating unit for the speed command value V _M by adding the value obtained by multiplying the speed ball Jitibu feedback gain K _VP to the actuator velocity V In the equilibrium cargo handling device provided with the speed command value V _M to the drive circuit of the actuator so that the work can be moved up and down with a light force, in the calculation unit, a small speed positive feedback gain K _{VP is applied} to the actuator when the actuator is low speed. A control circuit for a balanced cargo handling device provided with a circuit for multiplying the speed V by a large speed positive feedback gain K _VP when the actuator is at a high speed.

As a result, when the work is moved at a high speed, the speed positive feedback gain becomes large, so the operating force can be lightened, and when the work is moved at a low speed, the speed positive feedback gain becomes small, so that an appropriate operation force can be obtained and positioning can be performed accurately. .

〔Example〕

 An embodiment of the present invention will be described below.

First, the operating force f in the balance mode calculation unit 13 described above is The steady operating force (operating force when moving up and down at a constant speed) f∞ is Since it is proportional to the motor circuit speed V, it becomes a straight line (a) in the chart of FIG. 5, and if the force feedback gain K _F and the speed positive feedback gain Kvp are increased from the equation (2), the operating force becomes smaller. I understand.

Further, in general, the operating force at the time of minute positioning (at low speed) is too heavy, and of course it is too fluffy to be positioned when it is too light, and it is difficult to perform positioning, and an appropriate operating force is required.

On the other hand, when moving at high speed, it is better to be lighter because it will cause fatigue if the operating force is heavy, so if you increase the force feedback gain K _F and velocity positive feedback gain Kvp to decrease the operating force, it will become too light at low speed. I will end up.

Therefore, in the present invention, the speed positive feedback gain Kvp is changed according to the actuator speed so that an appropriate operating force can be given at a low speed and the operating force can be made light at a high speed.

An example will be described below.

As shown in FIG. 1, the balance mode calculator 13 is provided with a multiplication circuit 24 for multiplying the actuator speed signal V by the speed positive feedback gain Kvp.
When the actuator absolute speed | V | is smaller than the predetermined speed threshold V ₀ , that is, Kvp ₁
The multiplication of V is performed, and when it is large, that is, in the high speed range, the multiplication of the following equation is performed.

Kvp ₂ (V−V ₀ ) + Kvp ₁ · V ₀ (3) Kvp ₂ (V + V ₀ ) −Kvp ₁ · V ₀ (4) However, when V> 0, the formula (3) is the formula (4). Is when V <0, and Kvp ₁ <Kvp ₂ .

Therefore, the velocity positive feedback gain Kvp is small at low speed (Kvp ₁ ) and large at high speed (Kvp ₁ ).
vp ₂ ), the velocity positive feedback amount becomes Kvp ₁ · V at low speed, and at the time of high speed, the above equation (3),
It becomes as shown in the equation (4). If this is expressed in a diagram, as shown in FIG. 2, the gradient becomes large with the speed threshold V ₀ as a boundary, and the operating force is not so much at speeds above the speed threshold V ₀ as shown by the straight line (b) in FIG. Does not grow.

Then, the actuator speed command V _M The low _{speed, V M = K F (W} 0 -F L) + Kvp and with becomes ₁ · V ... (5), the high _{speeds, V M = K F (W} 0 -F L) _{+ Kvp 2 · (V-V} 0) + Kvp 1 · V 0 ... the _{(6) V M = K F} (W 0 -F L) + Kvp 2 · (V + V 0) -Kvp 1 · V 0 ... (7).

In the above embodiment, the speed positive feedback gain Fvp is set in two stages, but it is set in multiple stages (Kvp ₁ <Kvp ₂ <Kvp
₃ <Kvp ₄ ...), or continuously, for example You can also use

Next, a specific example of the balance mode calculation unit 13 will be described with reference to FIG.

Deviation between the force sensor signal F _L and the weight stored value W ₀ by the operational amplifier 30 (W ₀ -Fe) while calculating a the deviation (W ₀ -Fe)
Is multiplied by the force feedback gain K _F and output as a force feedback signal K _F (W ₀ −F _L ) to the point A.

The actuator speed signal V is input to the first comparator 31, the normally-open contact RY1a and the normally-closed contact RY1b of the first relay, respectively.
The output side of the comparator 31 is connected to the base of the switching transistor 32 of the coil RYC1 of the first relay so that the coil RYC is excited when V> 0, and the normally closed contact RY1b
Connected to the output side of the normally open contact RY1a via the inverter 33, and | V | is the second comparator 34 even when V> 0 and V <0.
It is input to the first comparator 35.

The speed threshold V ₀ is input to the first comparator 35, the second comparator 36, and the comparator 34, and the first comparator 35
Kvp ₂ (| V | −V ₀ ) is calculated in 35 and the second comparator 36
Kvp ₁ · V ₀ is calculated with and the values of both are added
The addition is made at 37, and the result is inverted by the normally open contact RY1a, normally closed contact RY1b of the first relay and the inverter 38 and output to the point B.

The second comparator 34 turns on the switching transistor 39 of the coil RY2c of the second relay when | V | −V ₀ <0.

The actuator speed signal V is sent to the third comparator 40.
Kvp ₁ is multiplied, is output to the point C as Kvp ₁ · V.

The value at point B is sent to the adder 41 via the normally closed contact RY2b of the second relay, and the value at point C is normally open contact RY2a of the second relay.
Sent to the adder 41 via the force feedback signal KF
(W ₀ −F _L ), so that when the speed is lower than the speed threshold V ₀ , that is, | V | −V ₀ <0, the second
The normally open contact RY2a of the relay is turned on, and the output at point C is added to the force feedback signal K _F (W ₀ −F _L ) by the adder 41, and the actuator speed command V _M becomes the value of the above formula (5), When the speed is higher than the speed threshold V _{0, the} normally-closed contact RY2b of the second relay is ON, so the output at point B is added to the force feedback signal K _F (W ₀ −F _L ) by the adder 41 and the actuator speed command is issued. Is the value of the above formula (6) or formula (7).

〔The invention's effect〕

When the work is moved at a high speed, the speed positive feedback gain becomes large, so the operating force can be lightened, and when the work is moved at a low speed, the speed positive feedback gain becomes small, so that an appropriate operation force can be obtained and the positioning can be performed accurately.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, FIG. 1 is an explanatory view of a balance mode calculation unit, FIG. 2 is a chart showing a relationship between actuator speed and speed positive feedback amount, and FIG. Explanatory drawing of a specific example of the mode calculation unit,
FIG. 4 is an explanatory view of a conventional balance mode calculation unit, FIG. 5 is a chart showing the relationship between actuator speed and operating force, and FIG.
The figure is an explanatory view of the configuration of the balanced cargo handling apparatus.

Claims (1)

[Claims] 1. An actuator for raising and lowering a work, a drive circuit for driving the actuator, a speed commander for inputting a speed command by an operator, a force detector for detecting a load, and a speed detector for detecting an actuator speed. And a position detector that detects the actuator position, and an arithmetic circuit that outputs an input signal to the drive circuit of the actuator based on the detection signal of each detector and stores the weight of the workpiece. Force detection signal _FL and weight memory value
A value to the deviation W ₀ -F _L multiplied by the force feedback gain K _F and W _0, the calculating unit for the speed command value V _M by adding the value obtained by multiplying the speed ball Jitibu feedback gain K _VP to the actuator velocity V In the equilibrium cargo handling device provided with the speed command value V _M to the drive circuit of the actuator so that the work can be moved up and down with a light force, in the calculation unit, a small speed positive feedback gain K _{VP is applied} to the actuator when the actuator is low speed. A control circuit for a balanced cargo handling apparatus, comprising a circuit for multiplying the speed V and a large speed positive feedback gain K _VP for multiplying the actuator speed V when the actuator is at a high speed.