JPH06254787A - Noncontact hand - Google Patents

Abstract

PURPOSE:To provide a noncontact hand to perform attraction and support of an object partially provided with a ferromagnetic substance or a magnet in a non4contact state and be used in a state to mount on the manipulator of a robot. CONSTITUTION:A noncontact hand comprises an electromagnet 1 to attract an object 6 partially provided with a ferromagnet substance or a magnet; a moving position detecting sensor 2 to detect the position of an object 6: and a control to levitate and support the object 6 through drive of the electromagnet 1 by means of an output signal from the sensor 2. The non-contact hand is functioned as a hand for a robot through operation of the object 6 by moving the sensor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact hand which is used by being attached to a robot or other manipulator for non-contact operation of an object having a ferromagnetic material or a magnet.

[0002]

2. Description of the Related Art Conventionally, as a hand used for a robot or other manipulator, there is a grip type hand.
They use hydraulic, pneumatic or electric motors as a drive source, and operate them by bringing them into contact with the target object. Therefore, it is not suitable for the operation of a material whose surface condition is remarkably changed by contact such as a material just after coating, or an material which is likely to be exploded or cracked by contact. However, if there is a hand that can operate the above things in a non-contact state, it is considered to be extremely useful industrially. In addition, the technology of levitating an object by magnetism to make it non-contact has been known for a long time, and there are bearings and the like that utilize this, but in all of these, the target object is a gap from the magnet. Is very close to 1-2 mm or less, and the object itself is not the object of operation.

[0003]

In view of the above circumstances, the present invention utilizes the attractive force of an electromagnet to detect the movable position of the distance between the electromagnet and a ferromagnetic body or an object having a magnet as a part thereof. To provide a non-contact hand for gripping and transferring the object in a non-contact manner by controlling the sensor so that the object can be relatively large and the lifting operation of the object can be stably performed. , That is the subject.

[0004]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and its constitution is one to a plurality of electromagnets for attracting an object having a ferromagnetic material or a magnet as a part thereof. And a movable position detection sensor for detecting the position of the object, and a control device for controlling the electromagnet and the movable position detection sensor. The movable position detection sensor detects the position of the object, It is characterized in that the electromagnet is driven by the output signal of-and the object is levitationally supported in a non-contact state.

[0005]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 (a) is a diagram showing a basic configuration of a 1-degree-of-freedom non-contact hand according to an example of the present invention, and FIG. 1 (b) is a diagram showing a basic configuration of a 2-freedom non-contact hand. 1 (c) is a diagram showing a basic configuration of a three-degree-of-freedom non-contact hand, and FIG. 2 is an overall configuration diagram of a state in which the one-degree-of-freedom non-contact hand of an example of the present invention is combined with an articulated robot, FIG. 3 is a schematic diagram of a sensor mounting method and a feeding mechanism, FIG. 4 is a conceptual diagram of a position detecting method by a transmission type optical sensor, FIG. 5 is a block diagram of an electric circuit, and FIG. 6 is a high-power circuit diagram around an electromagnet. is there.

As shown in FIG. 1 (a), the basic 1-degree-of-freedom non-contact hand of the present invention uses an electromagnet as an actuator and controls the position of an object by using a position detection sensor. Has become.

The multi-degree-of-freedom non-contact hand is shown in FIG.
As shown in (b) and (c), a plurality of 1-degree-of-freedom non-contact hands are combined and each electromagnet is controlled independently. In a non-contact hand having three or more degrees of freedom, it is necessary to coordinate the movements of the movable position sensors. For example, Figure 1 (c)
In order to move up and down in the z-axis direction, the point O is moved up and down to move all the sensors A, B, C, and D up and down. -Try to raise B. Regarding the rotation around the y-axis, the movement of the sensors C and D is the same as that of the x-axis. A linear PID controller is used to control the electromagnet, and the non-linearity of the electromagnet is compensated by adjusting the PID gain. The gain adjustment can be performed relatively easily in the two degrees of freedom, but the adjustment becomes complicated in the three or more degrees of freedom. Therefore, the gain autotuning may be performed.

The operation of the present invention will be described below with reference to FIG. In the figure, 1 is an electromagnet attached to a flange F of the robot, 2 is a movable position detecting sensor attached so as to be vertically movable by a feed mechanism 3, 4 is a controller, 5 is a power amplifier, 6 is a ferromagnetic material or magnet
An object having 6a in its part, the position of the object 6 detected by the sensor-2 is used as a feedback signal, and the deviation from the position command given inside the controller 4 is changed into a control signal, and the power amplifier 5 To amplify and drive electromagnet 1,
The object 6 is levitated and supported. The position of the object 6 can be changed by changing the position command value of the controller 4, but since the movable range thereof is as narrow as 2 mm, a method of changing the position of the sensor-2 is adopted. In order to bring the object 6 from the ground to the air in a state of levitation support, after moving the non-contact hand to the sky above the object 6, the sensor-2 is lowered to a position where the object 6 is detected, and from that time point, the electromagnet 1 This is performed by starting the control and gradually raising the sensor-2. In addition, the integral gain is set to a small value in order to operate stably with respect to the change in the weight of the object 6 when it is levitated. After the levitation of the object 6 is completed, the integral gain is increased. In addition to this, as a gain adjustment rule, when the weight of the object 6 is small or when the distance between the object 6 and the electromagnet 1 is short, the proportional gain and the differential gain are decreased, and in the opposite case, the gain adjustments are also reversed. To

A specific example of the present invention will be described with reference to the drawings. a Device configuration FIG. 2 is an overall configuration diagram of a state in which a non-contact hand with 1 degree of freedom, which is the basis of an example of the present invention, is combined with an articulated robot, and the position of the object 6 is detected by a position detection sensor-2. When measured, the output of the sensor-2 is fed back to the controller 4. The PID gain adjusting volume 7 of the controller 4 is arranged so that the operator can adjust it. The output of the controller 4 is current-amplified by the power amplifier 5 to drive the electromagnet 1 to attract and levitate the object 6 in a non-contact state. The feed mechanism 3 for moving the sensor-2 is driven by the motor 8, and the sensor 8 is driven by the drive.
2 is moved up and down. The motor 8 is driven by the driver 10 amplifying the output of the position controller 9. The drive system of the sensor-2 constitutes a position control system which amplifies the deviation from the command value of the feed amount indicator 12 using the output of the feed amount detector 11 as a feedback amount. The sensor
The position control system is independent of the controller 4, and the PID gain of the controller 4 has to be adjusted depending on the position of the sensor, but the upper position of the sensor is reflected in the controller 4. Alternatively, a method of auto tuning may be considered. A feed mechanism including a sensor-driving motor 8 is also attached to the flange F for attaching the electromagnet 1 to the tip of the manipulator.

B Position Detection Sensor-FIG. 3 shows an example of the position detection sensor-2, which includes an LED.
The sensor 13 and the photo diode 14 are mounted on the sensor mounting jig 15 to form a transmission type. In order not to respond to visible noise such as that of a fluorescent lamp, the LED 13 is used in the infrared range, and the photodiode 14 is also adapted to it. As shown in FIG. 4, the position detection utilizes a change in the amount of light that strikes the light receiving surface of the photodiode 14 depending on the position of the object 6. Therefore, the detection range is narrow and is considered to be approximately proportional to the length of the light receiving surface of the photodiode 14, which is 2 in the embodiment.
mm. The transmissive sensor has the advantage that it can be of any shape as long as the object is optically opaque, and is stable because it is not easily affected by the reflection characteristics of the surface of the object. By doing so, the range of position detection can be expanded. The position detected by this sensor is not an absolute position from the electromagnet 1 to the object 6 but a relative position. The position sensor
In addition to the transmissive optical sensor, a reflective optical sensor, an eddy current position sensor, or the like may be used for 2 depending on the shape of the object 6 and the degree of freedom of the hand. When using the eddy current type position sensor, it is necessary to process the sensor output so as not to be affected by the magnetic field of the driving electromagnet.

C Control Circuit FIG. 5 is a block diagram of an electric circuit.
An ID control circuit was constructed. The transfer function G (s) of the control circuit has a proportional gain Kp, an integral gain Ki, and a differential gain Kd.
As shown in the following equation. However, s is a Laplace operator. G (s) = Kp + Ki.multidot.1 / s + Kd.s Incidentally, the control may be performed by software using a personal computer or the like.

D Power Supply Method The power supply method to the electromagnet 1 uses PWM (pulse width modulation method) to reduce the heat loss of the amplifier. The pulse cycle is about 2 KHz. In the embodiment, DC23V is used as the power source for driving the magnet, and the electromagnet coil has a maximum of 5
A current of about A can be stably supplied. As shown in FIG.
A diode 17 mounted in parallel with the electromagnet coil 16 is used as a flywheel diode. Even if the coil is pulse-driven by this diode 17, a direct current flows through the coil. As the output stage switching device, a bipolar power transistor module 18 is used, but a power MOSFET or the like may be used. When the power MOSFET is used, the pulse cycle can be increased to about 10 to 20 KHz, which enables smoother power supply.

E Electromagnet In the embodiment, a bar magnet is used to simplify the device,
An iron rod having a diameter of 10 mm and a length of 200 mm was used for the iron core 1a, and an appropriate taper was attached to the tip facing the object. Excitation coil
For 1b, a formal wire with a diameter of 0.7 mm was wound around 600 turns. The winding resistance was 1.3Ω. Furthermore, when creating a strong magnetic field,
It is necessary to increase the number of turns of the coil 1b, and also to prevent the iron core 1a from magnetic saturation. The magnet type is not limited to the bar magnet, and a more suitable magnet shape and type can be considered.

Actually, a non-contact hand with the above 1 degree of freedom was used to coat the surface with a ferromagnetic material, the diameter was 38 mm, and the weight was about 25 g.
, Or an iron ball with a diameter of 17.5 mm and a weight of 21.7 g, the position can be changed within a distance of 4 to 8 mm from the electromagnet 1 and about 10 mm below the electromagnet 1. It was confirmed that the above-mentioned object placed on the floor could be levitated to the control position. Also, when this non-contact hand was attached to an articulated robot and a movement test was performed, the hand showed a swaying motion due to the degree of freedom of the hand, but the robot showed a sudden movement. Unless you
The object could be stably supported by floating.

[0015]

The present invention is as described above, and it is possible to suspend and support an object having a ferromagnetic material or a magnet in its part as if it were suspended from above and without contact. For example, a hand that is attached to a robot or other manipulator to operate an object whose surface condition is significantly changed by contact, such as an object that has just been painted, or an object that is liable to explode or crack due to contact. Is suitable as

[0016]

[Brief description of drawings]

FIG. 1A is a diagram showing a basic configuration of a non-contact hand having one degree of freedom according to an example of the present invention. FIG. 1B is a diagram showing a basic configuration of a non-contact hand having two degrees of freedom. Figure showing the basic configuration of the non-contact hand

FIG. 2 is an overall configuration diagram of a state in which a non-contact hand having one degree of freedom according to an example of the present invention is combined with an articulated robot,

FIG. 3 is a schematic view of a sensor mounting method and a feed mechanism,

FIG. 4 is a conceptual diagram of a position detection method using a transmissive optical sensor.

FIG. 5 is a block diagram of an electric circuit,

FIG. 6 is a high-voltage circuit diagram around the electromagnet,

[Explanation of symbols]

 1 Electromagnet 1a Iron core 1b Electromagnetic coil 2 Movable position detection sensor-3 Feed mechanism 4 Controller 5 Power amplifier 6 Object with ferromagnetic material or magnet in part 6a Ferromagnetic material or magnet in object 7 PID gain adjustment Volume 8 Sensor-driving motor 9 Position controller 10 Driver-11 Feed amount detector 12 Feed amount indicator 13 LED 14 Photodiode 15 Sensor-mounting jig 16 Electromagnetic coil 17 Diode 18 Power -Transistor module R Robot F Robot R flange

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[Procedure amendment]

[Submission date] July 22, 1992

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of a non-contact hand having one degree of freedom according to an example of the present invention.

FIG. 2 is a diagram showing a basic configuration of a two-degree-of-freedom non-contact hand.

FIG. 3 is a diagram showing a basic configuration of a three-degree-of-freedom non-contact hand.

FIG. 4 is an overall configuration diagram of a state in which a non-contact hand with one degree of freedom according to an example of the present invention is combined with an articulated robot.

FIG. 5 is a schematic view of a method of attaching a sensor and a feeding mechanism.

FIG. 6 is a conceptual diagram of a position detection method using a transmissive optical sensor.

FIG. 7 is a block diagram of an electric circuit.

FIG. 8 is a high-voltage circuit diagram around an electromagnet.

[Explanation of reference numerals] 1 electromagnet 1a iron core 1b electromagnetic coil 2 movable position detection sensor 3 feeding mechanism 4 controller 5 power amplifier 6 ferromagnetic material or object having magnet part 6a ferromagnetic material or magnet in object 7 PID gain Adjustment volume 8 Sensor drive motor 9 Position controller 10 Driver 11 Feed amount detector 12 Feed amount indicator 13 LED 14 Photodiode 15 Sensor mounting jig 16 Electromagnetic coil 17 Diode 18 Power transistor module R Robot F Robot R flange

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

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 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Horita 30 Shodozaka, Miai-cho, Okazaki-shi, Aichi Nisshinbo Co., Ltd.

Claims (1)

[Claims] 1. One or a plurality of electromagnets for attracting an object having a ferromagnetic material or a magnet in its part, a movable position detecting sensor for detecting the position of the object, and the electromagnet and the movable position detecting sensor. A control device for controlling, the position of the object is detected by the movable position detection sensor, an electromagnet is driven by an output signal of the sensor, and the object is levitationally supported in a non-contact state, and The sensor
A non-contact hand, characterized in that it is made to function as a robot hand by moving the object to operate the object.