JPS60118480A - Force applying device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (3) Technical Field of the Invention The present invention relates to an article processing apparatus, particularly an article processing apparatus such as an industrial robot used for precision machine assembly, which is used for gripping an object to be operated. Regarding force, this article relates to an article processing device that enables minute force control.

(B) Conventional technology and problems So-called F/A (7 actly automation),
As the FMS (Flexible Manufacturing System) progresses, robots are increasingly being introduced into production processes. on the other hand.

For example, work that requires delicate work such as processing of cattle conductors, assembly of peripheral magnetic heads, or soft foods.

Automation of materials inspection, etc. is lagging far behind. This is due to the fact that, although it is thought that automation will be promoted by highly intelligent robots, there is currently no four-pot system that can control minute forces on the Durham order, for example. In other words, automation of micro work that handles micro parts.

This has been difficult to achieve because there are no robots capable of micro-force control.

For example, in the conventional method, when controlling two gripping forces, a pressure sensor is provided at the gripping portion of the fingers, and the gripping force is controlled by the width of the fingers. In this case, it is necessary to switch between the 2-position control mode and the force control mode in accordance with the work timing, and not only is the timing of switching difficult, but also the difference in gain between the position control mode and force control mode at the time of switching. This is influenced by the moving speed of the fingers when one grip is carried out, and since it is not constant, vibrations and collisions occur when the fingers come into contact with one grip. Therefore, it is almost impossible to control one gripping force within a small range. Further, two control circuits and two sensors are required for nine-position control and two for force control, which increases the cost.

(C) Object and Structure of the Invention The present invention aims to solve the above-mentioned problems, and aims to provide an article processing device capable of controlling minute force to grip an object to be operated with a specified gripping force. Therefore, the article processing apparatus U of the present invention is an article processing apparatus equipped with a force application mechanism that receives a force application command and applies the commanded force to the article, wherein the force application mechanism includes a drive unit that generates a force, a force applying means that is displaced by a force from the drive unit and applies a force to the article; and a force applying means that receives an amount corresponding to the displacement of the force applying means and the force applying command, and applies the force based on those signals. The device is characterized in that the device includes a drive control device that controls the drive section so as to apply a force to the article in accordance with the force application command.

Another aspect of the present invention is a force applying mechanism that receives a force applying command and applies the commanded force to an article.

The article processing apparatus includes a moving mechanism that moves the force applying mechanism, wherein the force applying mechanism is displaced by a drive section that generates force and a force from the drive section.

A force applying means for applying a force to an article; receiving an amount corresponding to the displacement of the force applying means and the force applying command; and based on those signals, the force applying means applies a force applying command to the article. and a drive control means for controlling the drive section so as to apply a corresponding force.

Still another aspect of the present invention includes a force applying mechanism that receives a force applying command and applies the commanded force to the article, and a moving mechanism that moves the force applying mechanism, and a driving mechanism that causes the force applying mechanism to generate the force. a force-applying means that is displaced by force from the drive section and applies force to the article; and receives the amount corresponding to the displacement of the force-applying means and the force-applying command, and receives the force applying command based on the signals. Displacement of the force applying means is controlled by an article processing apparatus including a drive control means for controlling the drive unit so that the force applying means applies a force corresponding to a force applying command to the article. It is characterized in that it includes a displacement detecting means for detecting displacement, and the moving mechanism is configured to be driven only based on a displacement signal from the displacement detecting means.

(Dl Embodiment of the Invention Fig. 1 is a sectional view of a robot hand showing the configuration of an embodiment of the present invention, and Fig. 2 is a control block diagram of the embodiment shown in Fig.・Arm, 2 is hand base, 3
-1 and 3-2 are a pair of finger parts, 4 is a parallel spring, 5 is a strain gauge, 6 is a voice coil motor, 7 is a permanent magnet, 8 is a coil, and 9 is a yoke.

10 represents a stopper, and 11 represents an object to be gripped.

The finger parts 5-1, 5-2 are formed to face the hand base 2 mounted on the robot arm 1, and in particular, the finger parts 3-1.
is formed of a rigid body, and the other finger portion 3-2 is formed such that its tip portion is supported by a pair of parallel springs 4.

The parallel spring 4 does not exert a restoring force against relative displacement of the tip end portion of the finger portion 6-2 in the 0 direction in the drawing. A strain gauge 5 is attached to the inside of each parallel spring 4.

This strain gauge 5 makes it possible to detect the displacement of the tip of the finger 6-2 relative to the finger base 2 from the deflection of the parallel spring 4.

The voice coil motor 6 is a yoke 9 to which a permanent magnet 7 is attached, and consists of a part fixed to the hand base 2 and a coil 8 part attached to the tip of the finger part 3-2. By applying and controlling current to the coil 8, the finger can be opened and closed in the 0 direction shown in the figure. As a result, the object 9 to be gripped 11 is gripped or released.゛It should be noted that the parallel spring 4 composed of two plate-shaped spring bodies has low rigidity only in the direction of movement, and relatively high rigidity in other directions, so the present invention is not limited thereto. , is suitable as a movement guide in one direction using a spring.

In the robot hand shown in FIG. 1, the gripping force is not controlled by the opening width of the hand, but by controlling the force generated by the voice coil motor 6, that is, by controlling the energizing current.

In other words, as a sensor.

A sensor for detecting displacement, such as the strain gauge 5, is used to control as follows.

Especially in the control of this embodiment.

■ Positive feedback is given to the signal from the strain gauge 5 which is a displacement sensor so as to cancel the spring force of the parallel spring 4.

(2) The gripping force command value is calculated from the force generated by the voice coil motor 6.

Here, 9 generation force is.

Generated force - BII However, B: Air gap magnetic flux density of the voice coil motor l: Number of windings of the voice coil motor i: Calculated by the energizing current of the voice coil motor. Regarding this generated force, the voice coil motor 6
Unlike in the case of a rotary motor, the air gap magnetic flux density B is constant in the operating range and has high linearity with respect to the current of one generated force, so the calculated value and the measured value agree well.

A control block diagram of the robot hand shown in FIG. 1 is shown in FIG. 2. The current, speed, and displacement are each fed back. Note that in the following description, parameters are defined as follows.

e: Voltage between terminals of voice coil motor R: Resistance between terminals of voice coil motor I: Current between terminals of voice coil motor L: Inductance between terminals of voice coil motor B: Air gap magnetic flux density of voice coil motor l: Voice; Number of coil turns M: Moving part mass D = viscous damping coefficient: Spring constant of parallel spring X: Displacement of parallel spring 0°: Open loop gain of operational amplifier ■c:
Current feedback gain W: Velocity feedback gain Pe: Displacement feedback Gui/S Nira plus operator R (81: Grip command X (81: Displacement F (81: Grip force) Here, the characteristics of the voice coil motor 6.

e −R1+L″−10Bl)C=・・・・・・(11
i Bli-Mma + Dx 10kx ・・・・・・・・・・・・
...(2).

In Fig. 2, if we take the transfer function from 9 gripping commands R (81) to the displacement of the parallel springs X (81).

・・・・・・・・・・・・・・・(3) Therefore, when R(81 changes in a stepwise manner, the steady value of X(81) is.

becomes. That is, this control system is expressed by the above equation (4) and has a steady position error.

Here, since Oc is generally a very large value of 80 db to 100 db, the steady position error is almost zero. This is not preferable for controlling nine robot hands. If the width of the object to be grasped is not accurately known, the voice coil motor 6 will act as a spring with the spring constant shown in (4) 2 in the low frequency band due to an error in the width indication, resulting in a large force. 2, it becomes impossible to control the gripping force.

Therefore, it is ranked 1st in 9 examples! A method is adopted in which the gain of the ILIiI difference is kept as low as possible within the range in which the control system is stable, thereby suppressing the generated force caused by the difference in 1st place 1iv4.

That is, as is clear from equation (4), since the displacement is fed back positively (the sign of h is negative), the above method can be realized. From equation (4).

All you have to do is adjust the container so that In this condition.

As is clear from the above equation (3), it appears as if the spring constant of the parallel spring of the finger has become extremely small. Therefore, the restoring force due to the spring becomes very small with respect to the 8-position error. In the experiment, the spring constant was apparently o, 1
(f/m).As a result,
When the opening/closing stroke of the hand is ±2 [shoes], the maximum force generated on the object held is ±0.2 (5'), which is a very small value.

In this state, if only the gripping force component is input as R (81), the robot hand will be 9 ±0 regardless of the width of the object being gripped.
．． One object can be grasped with a force error within 217). Furthermore, if a gripping command with a sign opposite to that for gripping is given, the stopper 10 is contacted with a constant force and the opening state is established.

As explained above, the robot node of this embodiment can freely grasp the object 11 from a small force to a large force with a simple command of only one gripping force command without affecting the width of the object 11 to be grasped. be able to.

Further, the sensor is only a displacement sensor such as the strain gauge 5, and the structure is simple.

Low cost. In addition, by the signal of the displacement sensor.

By controlling the gripping force, it is also possible to measure the width of the gripped object, regardless of whether it is soft or hard.

By configuring the robot hand shown in FIG. 1, particularly the voice coil motor 6, as shown in FIG. 3, the robot hand can be made smaller and lighter. 6th
The figure shows an exploded perspective view of an embodiment of the article processing apparatus according to the present invention.

In the figure, numerals 2 to 5 correspond to those in FIG. 1, and 7-117-
2U permanent magnet, which corresponds to the yoke 9 shown in Figure 1, 7; 8' is a coil, which corresponds to the coil 8 shown in Figure 1; -1.9-2 is a yoke corresponding to the yoke 9 shown in Figure 1, 14 is a terminal, 15 is a bobbin, and 16 is a spacer.

17 and 1B represent screw holes.

If a cylindrical voice coil motor 6 as shown in FIG. 1 is used as the actuator for opening and closing the finger portion 5-1.3-2, the voice coil motor 6 must be installed in the opening and closing direction of the hand. No. Therefore, in this case, it is difficult to downsize/quantize the hand. Therefore,
As shown in Figure IJ3, a voice coil motor is used in which a flat coil 8' and permanent magnets 7-1, 7-2 are attached to the side of the hand.

A yoke 9-1 to which a permanent magnet 7-1 is attached.

Spacer 16 made of non-magnetic material such as aluminum
And the yoke 9-2 to which the permanent magnet 7-2 is attached is,
It is screwed into the screw hole 18 of the hand base 2. On the other hand, the flat coil 8' formed on the bobbin 15 is connected to the parallel spring 4.
On the tip side of the finger portion 5-2 that moves for opening and closing,
Fixed. As a result, when the terminal 14 is energized, the tip of the finger portion 6-2 is activated by the action of the coil 8' and the magnetic circuit.

Force will be applied in the direction of opening and closing the hand. In addition.

Voice coil motors as shown in FIG. 6 may be used on both sides of the node.

By realizing the voice coil motor using a flat coil as described above, space is saved and the hand can be made smaller and lighter.

By the way, it has conventionally been customary to use plastic such as resin for the bobbin of a general voice coil motor. However, if you use plastic etc. as the bobbin,
There are problems such as low thermal conductivity and softening due to heat generated by the coil. Therefore.

In order to solve this drawback, the bobbin 15 shown in FIG. 3 is made of aluminum. Aluminum material is lightweight and has high thermal conductivity.
It is also characterized by high rigidity. Additionally, aluminum has high electrical conductivity.

It has the advantage of inducing large eddy currents when moving through a magnetic field. The induction of this eddy current serves to increase the viscous damping coefficient of the voice coil motor.

Therefore, the stability of the control system can be improved.

However, it is necessary to ensure sufficient insulation between the coil 8' and the bobbin 150. Therefore, if the bobbin 15 is alumite-treated, good insulation can be obtained without affecting the number of turns of the coil 8'.

As a result of the above, a bobbin that is lightweight, has high rigidity, high thermal conductivity, and high damping can be realized at low cost. Note that the color of the alumite is preferably black. Black alumite treated bobbin 15
In order to prevent the coil from being scratched, a groove is dug to match the outer shape of the coil.

FIG. 4 shows a diagram for explaining an embodiment of attachment of the magnet plate shown in FIG. 3. In the figure, symbols 7-1 (or 7-2) and ? -1 (' or 9-2) corresponds to FIG. 5, and 19 represents a magnet fixing plate.

In the voice coil motor of the robot hand shown in FIG. 3, rare earth cobalt magnets, for example, are used as the permanent magnets 7-1 and 7-2 in order to reduce the size and quantity. Because this magnet has high holding power.

Rather than magnetizing the magnetic circuit after assembling it, a magnetized one is generally installed. In this case, if an attempt is made to arrange the magnets as shown in FIG. 6, the magnets will attract or repel each other, and a great deal of time will be wasted in assembling and adhering the magnets.

Therefore, by using a magnet fixing plate 19, for example, as shown in FIG. 4, the permanent magnets 7-1, 7-2 can be easily positioned. That is, the magnet fixing plate 19 is provided with a square hole that is slightly larger than the outer shape of the permanent magnet 7-1.7-2, and by fitting the permanent magnet 7-1.7-2 into this hole, the yoke 9 -1. The magnet position is determined on the plane 9-2. If the magnet fixing plate 19 is made of non-magnetic material.

It can be made of any material. In addition, the magnet fixing plate 19
The thickness of the permanent magnet 7-1.7 should be approximately the same as the magnet thickness, or slightly thinner, in consideration of the magnet's protrusion due to attraction/repulsion force. By using the magnet fixing plate 19 as described above, the permanent magnet 7-1.7 -2 is not only easier to position and can be manufactured in a short time, but also the adhesive process between the permanent magnet 7-1.7-2 and the yoke 9-1.9-2 is no longer required, resulting in a significant cost reduction. become able to.

The robot fighting hand as shown in FIG. 1 or 3 has an object to be manipulated, that is, an object to be grasped.

If the gripper is of a constant size, the structure is relatively simple, so it can be used as a gripper that can control minute forces.
It's extremely useful. However, the opening/closing span of /) is
Although it depends on the length of the parallel spring 4.

For example, if the size of the gripped object changes, with a limit of about 4 degrees, the robot hand will need to be replaced accordingly.

FIG. 5 is a perspective view of an embodiment of a robot hand improved in this respect, and FIG. 6 is a control block diagram of the embodiment shown in FIG. In the figure, 3-1 and 3-2 are finger parts corresponding to FIG. 1, 22 is a voice coil part of a voice coil motor, and 26
24 represents a magnetic circuit section of a voice coil motor, 24 a DC motor, 25 an angle encoder, 26 a feed screw, 28 a gripping force control section, and 29 a constant current amplifier.

In this embodiment, in order to be able to grip an object with a specified gripping force without being affected by the width of the object to be gripped, a pair of finger portions 5-1.3 are used as shown in FIG.
-2 is divided into left and right. Finger part 3-1.5-
A feed screw 26 is passed through the lower part of the feed screw 2.
The finger portion 3-1 side of 6 is.

For example, it has a left-hand thread, and the finger portion 5-2 side has a right-hand thread. By cutting the screws in the opposite direction like this,
When the feed screw 26 rotates, the finger portion 3-1 and the finger portion 5-
2 move in opposite directions and have variable spans.

The feed screw 26 is directly connected to a relatively small DC motor 24, and the rotation of the DC motor 24 provides the force for moving the fingers. The DC motor 24 is provided with an angle encoder 25, and the rotation angle of the DC motor 24 is determined by the angle encoder 25.
By knowing this, it is possible to control the span of the hand.

The upper tip portion of the finger portion 5-2 is supported by a parallel spring as explained in FIGS. 1 and 3, and the finger portion 5-2 is
-2, the voice coil section 22 and the finger section 3 attached to the upper part of the
A voice coil motor constituted by a magnetic circuit section 26 attached to the lower part of the finger section 26 applies force in the opening/closing direction of the finger section. Note that the internal configuration of the voice coil motor is the same as that explained in FIG. 3, so a detailed explanation will be omitted.

In FIG. 6, the 9-grip force control section 28 performs the same control as that shown in FIG. 24, and the detected value by the angle encoder 25 is fed back.

In other words, the voice coil motor has a gripping force, and the DC motor 2
4 is used to control the gripping width, and 9 is a trap so that accurate gripping force can always be controlled regardless of the width of the gripped object.

If there is no voice coil motor and the gripping force is controlled only by a DC motor that performs span control, there will be a dead zone in the control system due to the friction of the DC motor, feed screw, etc. 9.For example, force control of less than a few tensors is nearly impossible.

In this embodiment, it is of course impossible to eliminate the span error caused by the dead zone.

Since the voice coil motor performs the above-mentioned gripping force control, force control that is not affected by span displacement is possible within the range of 2, for example, a span error of ±2.
If it is within the range of [Maro], it is possible to accurately control the gripping force.

In other words, if the width of one grasped object is given with an accuracy of, for example, within ±2 [mm], the robot node of this embodiment can grasp the object with accurate grasping force. In particular, since there is no friction in the support system of the voice coil motor, it is easy to achieve highly accurate force control that is unaffected by disturbances caused by frictional force. Wear.

In the robot hand described in the embodiment shown in FIG. 5, the gripping force is controlled by a voice coil motor,
The span control by the DC motor 24 is performed completely independently. In connection with these controls, 1. For example, if the control of the DC motor 24 can be controlled based on the signal from the displacement sensor provided on the spring body part of the finger part 6-2, micro force control with better accuracy and better coordination can be achieved. It is thought that this will become possible.

FIG. 7 is a perspective view of another embodiment of the present invention, FIG. 8 is a schematic diagram for explaining the embodiment shown in FIG. 7, and FIG.
Figure 0 is a block diagram of the force control system for the embodiment shown in Figure 7, and Figure 11 is a diagram of the robot excluding the voice coil motor.
FIG. 12 is a right side view of the robot 9 node shown in FIG. 11, FIG. 13 is a sectional view taken along the line shown in FIG. 15 is a right side view of the robot hand shown in FIG. 14, and FIG. 16 is a right side view of the robot hand shown in FIG. FIGS. 17 and 18 are diagrams for explaining the configuration of the nut portion of the screw feeding mechanism.

In FIGS. 7 to 18, reference numerals 5-1.3-2.
4.5 corresponds to FIG. 1, 22 to 24 correspond to FIG. 5, 50 is a stopper, 31 is a base, 62 is a bearing, 40 is a projection, 41 is a side 7" plate, 45 is a The elastic body, 46 represents a nut, and 47 represents a female screw portion in the finger portion.

As can be seen from FIG. 9 and other figures, the robot hand of this embodiment has the same external structure as the robot hand of the embodiment shown in FIG. The finger parts 5-1.5-2 are provided separately, and the right-hand thread and the left-hand thread are attached to each finger part 5-1.5.
It is mounted on a feed screw 26 carved corresponding to -2. The left and right fingers open and close as the DC motor 24, which is directly connected to the feed screw 26, rotates. A parallel spring 4 is attached to the finger portion 5-2.
A square hole is provided so that a square hole can be configured, and a strain gauge 5 is pasted on the spring surface as a displacement sensor.

In such a configuration, the voice coil motor mounted on the finger portion 3-2 operates as the main motor, and the DC motor 24 that rotates the feed screw 26 operates as a slave. That is.

When the object cannot be gripped only by the displacement of the voice coil motor, the DC motor 24 rotates to achieve the required span, thereby controlling the span to a predetermined value. Although it is not impossible to control the force with this span control alone9, normally, since the friction of a moving mechanism such as the feed screw 26 is large, there is a dead zone in the control system, and as mentioned above, it is difficult to control the force on the gram order. . That is.

In order to control a force that is less than the frictional force of the moving mechanism, a sophisticated control method must be used, and a large amount of time is required for control design and adjustment.

The robot hand according to the present invention is composed of a voice coil motor that uses a parallel spring 4 as a support mechanism and applies a gripping force to the fingers 3-2, and a DC motor 24 that drives a feed screw 26 that has large friction and can be stably controlled. By adopting a hybrid actuate mechanism, micro-force control can be performed very easily. In addition, the voice coil motor mentioned above.

It has a voice coil section 22 and a magnetic circuit section 25, and has a structure similar to the voice coil motor described above in FIG. 3 and the like.

Next, the micro-force control mechanism of this embodiment will be explained through the control method of the hybrid actuator mechanism.

Note that the parameters used in FIGS. 9 and 10 and in the following explanation are as follows.

'ox(sl: Input to DC motor U□ (81: Input to voice coil motor 5 S: 2-glass operator 0□, Oc: Open loop gain of logic operation element Dm+Dc
: Viscous damping coefficient B : Air gap magnetic flux density l of the voice coil motor : Length of the windings of the voice coil motor Lc : Inductance Rc of the voice coil motor : Resistance between terminals of the voice coil motor Ic : Current feedback constant vc of the voice coil motor :Velocity feedback constant Pc of voice coil motor:Position feedback constant Mc of voice coil motor:Mass of moving part of voice coil motor k:Spring constant of parallel spring of finger part X6:Displacement of parallel spring of finger part Km:of DC motor Induced voltage constant Lm: Inductance Rm of DC motor: Resistance between terminals of DC motor Io: Current feedback constant of DC Tanabata m = Speed feedback constant of DC motor Pl: Position feedback constant M of DC motor: Load mass minus the mass of the moving part of the voice coil motor , the amount of displacement of the parallel spring portion is detected by a strain gauge 5 attached to the parallel spring 4 shown in FIG. As can be seen from the block diagram of the force control system shown in FIG. The same parallel spring displacement and speed signals as those of the voice coil motor are negatively fed back to the motor 24. That is, it is characterized in that the amount of feed by the feed screw 26 and the gripping force by the fingers 5-1, 5-2 are controlled only by the amount of displacement of the parallel spring 4 without detecting the displacement of the feed screw 26. The amount of positive feedback by the displacement signal to the voice coil motor is determined in the same manner as the example explained in FIG. 2.

For such control systems, voice coil motors.

The required gripping force Us(Sl+Ul(81) is given to the DC motor, and the input signal is set to UtlSl-0.The voice coil motor is 9, for example, a stopper 30 directly connected to the voice coil 22' schematically shown in FIG. is displaced inward with a constant force until it hits the stator of the magnetic circuit section 23'.Then, the DC motor 24 rotates so that the displacement xc of the parallel spring 4 becomes zero.

At this time, as is clear from FIG. 9, no matter how much the DC motor 24 rotates, the displacement x1 of the parallel spring 4 cannot be made zero. (7'c, except when the acceleration generated by the DC motor 24 is very large.) Therefore, the DC motor 24 continues to rotate, the fingers move inward, and the span is the width of the object to be grasped. When it hits the object to be grasped.

Then, before the hand's motor system grasps the object.

Mc circle + (Mm + Mc) Wm = -Dmim + KmIm
-Fr """-・-・fatMe('x-+'ff
1c) --kxc -DciC+B1Ic """"
”...171r, J, --Ra+1., +Bm-Km
im ・-------------...fs) Lc also --R
cm+E, -13/circle ・・・・・・・・・・・・(
9) The problem with 2) is from the point of contact with the object to be grasped.

It is as follows.

MI! l'4--kxc +BI Ic +KmIm
-Fr -(Dm+Dc) kg ”'””””'
α1L-1,, -R Engineering I,, +E---Island...
・・・・・・・・・IL, i, --Rcl, 10L -B
/Sentence.・・・・・・・・・・・・ If the a2 contact point is the initial value (time t-0), the control system
The result will be as shown in the figure. The transfer function of this control system can be expressed as follows. Here, the open loop gain of the operational amplifier is.

0! China It is assumed that

+Fr(Sl ・・・・・・・・・・・・・・・Q Teng also +Ui(Since it is set as 81-0, the target manpower U
, (81, Frictional force prts+ and output X (81) A linear 'relationship holds.

・・・・・・・・・・・・・・・ I The following things are clear from this αth ceremony.

■This control system is observable and controllable.

■ Steady position error occurs for step input.

■ Steady position error occurs due to the presence of friction.

■ Two actuators can be controlled as one hybrid motor.

That is, the characteristics of formula 04 represent the same characteristics as in the case of one DC motor without using a voice coil motor, and no improvement can be seen in one-position control. However, the relationship between the gripping force F'' (81) generated by the fingers is as follows.

To express this, we set the 1-position feedback constant P6 as can be controlled without any problems. That is, accurate gripping force control is possible at the same time as contact, regardless of the steady position error of the DC motor 24. Furthermore, even if 'vc is set to zero, the damping of the system does not become zero due to the viscosity control (very small value) of the voice coil motor, and the system remains stable.

In order to establish the above aQ-th equation, the linearity of the displacement of the sensor that detects the spring constant k becomes a problem.
The parallel spring 4 shown in FIG. 8 has a structure that allows its rigidity to be weakened only in the -
Even with strain gauge 5, the influence of twisting etc. can be reduced by %'!
ff f K・If! ＜”＊＊＊”01-8゜gg□Can be done.

', it becomes possible to control from a minute force to a large force. In addition, even if there is a slight error, the object to be gripped is always gripped in a posture where the amount of displacement of the spring is almost zero. The movement mechanism also has excellent durability.

Furthermore, the response time of the nine robot hands is determined by the feedback constant of the DC motor, 9, as is clear from Equation 1 and Equation 10 above.In general, as P- becomes larger, the control system becomes unstable. This results in a two-oscillation state.At this time, *
The vibration force acts to dampen this oscillation. In this force control system, position errors due to friction do not affect the gripping force as described above.

The frictional force of the system can be increased, and by appropriately increasing the frictional force of the system, the connectivity of the system can be improved. In particular, if a feed screw mechanism is used as the movement mechanism, this is useful for improving the coordination of the system, since movement by the screw has relatively large friction.

The front view, side view, etc. of the robot hand shown in FIG. 7 are as shown in FIGS. 11 to 15. Here, FIGS. 11 to 13 show the voice coil motor with the voice coil motor removed, and FIGS. 14 and 15 show the voice coil motor attached. In particular, a projection 40 as shown in FIGS. 11 and 14 is provided on the outside of the finger 3-2. This protrusion 40 is.

When the hand is moved open by the feed screw 26, it finally comes into contact with the side plate 41 fixed to the base 61.

In conventional robot hands, the hand is generally opened using a displacement command. However, if the hand is opened using a displacement command, a displacement error will occur.

This causes strain, which is not desirable. In this example.

Since a projection 40 serving as a stopper is provided on the outside of the finger 6-2 on which the voice coil motor is mounted, the hand can be opened by force control. That is, the opening control is performed using the same control as when the hand is closed. In the block diagrams of the force control system in FIGS. 9 and 10, when the hand is opened, a signal with the opposite sign to that when the hand is closed is given as U2 (81).
This displacement signal is transmitted to the DC motor 24 by the outward displacement of
0 control system, and the hand is moved to the open side by the moving mechanism using the feed screw 26.

The protrusion 40 contacts the side plate 41. The protrusion 40 is the side plate 4
1 and is pressed with a predetermined force, the parallel spring 4 returns to its original position and the finger stops moving. Thus, by force control.

Since the opening and closing of the hand can be controlled, straining does not occur in the moving mechanism, etc.

Using the same control principle, the object to be manipulated can be gripped by a so-called internal grip. Namely.

For example, if the tip of the finger is
.

Make it like 5-2'. from the closed position.

For example, a tubular gripping object 1 as shown in FIG.
1', if the opposite sign Us (81) is given to the control system, as shown in FIG.
1' from the inside. Of course, the shape of the finger tip etc.
It is not limited to what is shown in FIG. 16, and nine various modifications are possible.

By the way, as mentioned above, in the robot node of this embodiment, it is better to have an appropriate amount of friction in the moving mechanism using the DC motor. Therefore.

Although the feed screw 26 is suitable, it is even better to use the following method. As shown in FIG. 17 and FIG. 18, which is a partial cross-sectional view thereof, the nut portion of the feed screw 26 is connected to the 7th threaded portion 47.47' of the finger portion 46.46'.
A so-called backlash-less structure is employed in which an elastic body 45, 45' such as a rubber plate is sandwiched between the two. By doing this, the nut 46 and the non-threaded portion 47 of the finger part receive a force in the direction of the arrow shown in FIG. 18 by the elastic body 45.
This prevents rattling between the feed screw 26 and the finger portions 5-1, 5-2. Further, it is also possible to adjust the friction force to a predetermined value.

FIG. 19 shows another embodiment of the present invention, and FIG. 20 shows an example of a circuit used in the embodiment shown in FIG.

In the figure, code 5-1.3-2.22.25.24.26
corresponds to FIG. 7, 50 is an angle encoder, 51 is a signal cable, 52 is a power supply, and 55 is an operational amplifier.

54 is an analog-to-digital converter, 55 is a counter, 5
6 represents a processor (CPU), and 57 and 58 represent input/output ports.

In the robot Φ hand shown in FIG. 7 mentioned above,
Even if the width of the object to be manipulated is unknown, the object can be grasped. On the other hand, it is often necessary for the control unit of the robot to detect the width of the object gripped by the robot hand. Therefore, as shown in FIG. 19, an angle encoder 50 is attached to one end of the shaft rotated by the DC converter 24 for span control, and a circuit for detecting the width is provided, for example, as shown in FIG. . In addition.

The other parts are the same as the example described in FIG. 7 and subsequent figures, so detailed explanation will be omitted.

In Figure 1B20, the amount of displacement due to the parallel spring is.

Detected by strain gauge 5, operational amplifier 55
The signal is amplified by the analog-to-digital converter 54 and converted into a digital quantity. Processor 56
can be read via input/output port 57. On the other hand, the output of the angle encoder 50 passes through the signal cable 51 to increase or decrease the counter 55, and the processor 56 can read the kakunta value corresponding to the amount of rotation angle from the input/output port 58.

The measurement line for the width of the object to be held is performed as follows. First, in order to detect the zero point, close the hand without grasping anything. At that time, the counter 55 is reset, and the value related to the displacement due to the output of the strain gauge 5 is stored and set as an initial value. Next, the object to be gripped, which is the object of width measurement, is gripped with a minute force using the control method described above, and the value of the counter 55 at that time and the offset amount from the initial displacement value of the strain gauge 5 are calculated. are multiplied by a conversion value determined in advance through experiments, etc., and then added together.

By doing this, the robot hand of this embodiment becomes
Since it is possible to grasp objects with minute force, it is possible to easily measure the width of two or six soft objects, for example.

(El) As described in detail, according to the present invention, it is possible to grip an object to be operated with arbitrary minute force, for example on the Durham order.Furthermore, the width of the object to be gripped is not constant. Even if the case is different, it is possible to grip an object with a predetermined and stable force.Therefore, for example, magnetic heads used in information processing equipment.

It will now be possible to widely introduce robots in fields that have traditionally been difficult to automate, such as handling minute parts such as IC chips.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a robot hand showing the configuration of an embodiment of the present invention, FIG. 2 is a control block diagram of the embodiment illustrated in FIG. 1, and FIG. 6 is an embodiment of the robot hand according to the present invention. FIG. 4 is an explanatory diagram of the assembly of an embodiment of the robot hand shown in FIG. 3, FIG. FIG. 5 is a control block diagram of the embodiment shown in FIG. 7, FIG. 7 is a perspective view of another embodiment of the present invention, and FIG. 8 is a schematic diagram for explaining the embodiment shown in FIG. 9 and 10 are block diagrams of the force control system for the embodiment shown in FIG. 7, FIG. 11 is a front view of an embodiment of the robot hand excluding the voice coil motor, and FIG. 12 is a diagram of the embodiment shown in FIG. 11. A right side view of the illustrated robot Φ No. 1, FIG. 13 is a sectional view taken along the line A-A' shown in FIG. 11, and FIG. 14 is a front view of an embodiment of the robot hand shown in FIG. 15 is a right side view of the robot hand shown in FIG. 3, FIG. 16 is a diagram for explaining the shape of one embodiment of the finger portion of the robot hand, and FIGS. 17 and 18 are screw feeding mechanisms. FIG. 19 is a diagram for explaining the configuration of one embodiment of the nut portion, FIG. 19 is a diagram showing another embodiment of the present invention, and FIG. 20 is a diagram showing an example of a circuit used in the embodiment shown in FIG. In the figure, 3-1 and 3-2 are finger parts, 4 is a parallel spring, 5 is a strain gauge, 6 is a voice coil motor, 8 is a coil, 22 is a voice coil part, 23 is a magnetic circuit part, and 24 is a DC motor. , 26 is a feed screw, 40 is a projection, 45 is an elastic body, and 50 is an angle encoder. Patent applicant Fujitsu Limited

Claims (1)

[Claims] (1) In an article processing apparatus equipped with a force applying mechanism that receives a force applying command and applies the commanded force to an article, the force applying mechanism is a drive unit that generates the force. and. a force applying means that is displaced by a force from the drive unit and applies a force to the article; and a force applying means that receives an amount corresponding to the displacement of the force applying means and the force applying command, and applies the force based on those signals. An article processing apparatus comprising: drive control means for controlling the drive section so that the means applies a force corresponding to a force application command to the article. (2) The article processing apparatus according to claim (1), wherein the drive section is a voice coil motor. (31) The article processing apparatus according to claim (2), wherein the voice coil motor includes at least a pair of magnet plates and a flat coil. (4) The voice coil motor The article processing apparatus according to claim 2 or 3, wherein the bobbin is made of an alumite-treated aluminum material. (5) The magnet of the voice motor. Claim (3), characterized in that the plate is formed by providing a hole with the dimensions of the magnet plate in a non-magnetic plate, and positioning the fixed position by inserting the plate into the hole in the non-magnetic plate. or the article processing apparatus according to item (4). (6) The force applying means includes at least two claw members, and the tip member of at least one of the claw members is responsive to displacement in the opening/closing direction of the claw member. The article processing apparatus according to claim (1), characterized in that the article processing apparatus is supported by an elastic member that generates an elastic force. (7) The article processing apparatus is characterized in that the elastic member is a parallel leaf spring. The article processing apparatus according to claim (6). (8) A force applying mechanism that receives a force applying command and applies the commanded force to the article, and a moving mechanism that moves the force applying mechanism. In the article processing apparatus, the force applying mechanism includes a drive section that generates force; a force applying means that is displaced by force from the drive section and applies force to the article; and a displacement of the force applying means. drive control means that receives the force application command and an amount corresponding to the force application command, and controls the drive unit so that the force application means applies a force corresponding to the force application command to the article based on those signals; (9) The article processing apparatus according to claim (8), wherein the drive section is a voice coil motor. II. The voice coil motor. The article processing apparatus according to claim 9, wherein the coil motor includes at least one pair of magnet plates and a flat coil.Qυ The bobbin of the voice coil motor is anodized. The article processing apparatus according to claim 9 or claim 9, characterized in that the magnet plate of the voice coil motor is made of a non-magnetic plate with the magnet The article processing apparatus according to claim 1 or 1, characterized in that the fixing position is determined by providing a hole with the size of a plate and inserting the article into the hole of the non-magnetic plate. The force applying means includes at least two claw members, and the tip end member of at least one of the claw members is supported by an elastic member that generates an elastic force against displacement of the claw member in the opening/closing direction. An article processing apparatus according to claim (8). Q4: The article processing apparatus according to claim 01, wherein the elastic member is a parallel plate spring. 11. A force applying mechanism that receives a force applying command and applies the commanded force to the article; a moving mechanism that moves the force applying mechanism; a drive section in which the force applying mechanism generates a force; a force applying means that is displaced by a force from a part of the article and applies a force to the article; and an amount corresponding to the displacement of the force applying means and the force applying command, and the force applying means is applied based on those signals. an article processing device comprising: drive control means for controlling the drive unit to apply a force corresponding to a force application command to the article; and a displacement detection means for detecting displacement of the force application means; An article processing apparatus, wherein the moving mechanism is configured to be driven only based on a displacement signal from the displacement detecting means. Ql A patent characterized in that the drive unit receives a positive feedback of a displacement signal from the displacement detection means, and the moving mechanism uses the sum of the displacement signal and speed signal from the displacement detection means as a negative input signal. Claim No. a! Item processing device according to item 9.