KR100664483B1 - Robot having Selective Compliance Assembly Robot Arm: SCARA Robot - Google Patents

Abstract

A robot having an optional Compliance Assembly Robot Arm (SCARA) (hereinafter referred to as a "scar robot") includes a robot body, a base movable in a direction perpendicular to the robot body, A first arm having one end connected to the base so that the first arm can rotate in the horizontal plane, a second arm having one end connected to the opposite end of the first arm so that the second arm can rotate in the horizontal plane, and the second arm An R axis rotatably mounted to the free end of the arm, and stepping motors 12, 22, 32, and 42 are installed to move the first arm, the second arm, the R axis, and the base, respectively; An encoder is installed to calculate the stepping pulse of the motor. The pulse thus calculated is fed back to CPU1 so that the CPU1 can correct the error when an error is detected between the calculated number of pulses and the required number of pulses, and when the error is detected, the stepping motor can be stopped. The error is displayed.

Description

Robot having Selective Compliance Assembly Robot Arm: SCARA Robot}             

1 is a perspective view of the present invention Scara robot.

2 is a block diagram showing a first embodiment of the present invention.

3 is a flow chart showing operation of the first embodiment of the present invention.

4 is a block diagram showing a second embodiment of the present invention;

5 is a flowchart showing operation of the second embodiment of the present invention.

Fig. 6 is a block diagram showing a third embodiment of the present invention.

7 is a flowchart showing the operation of the third embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

5: error detection device 6: stop device

7: Display device 8: Confirmation device

10,20,30,40: stepping motor 12,22,32,42: stepping motor

50: first arm 51: second arm

52: R axis 53: expectation

The present invention relates to a scara robot.

Scara robots (robots with optionally assembled robotic arms upon command) are generally known as robots having multiple joint arms that can be moved in a horizontal plane. In more detail, the SCARA robot includes a first arm having one end articulated to the base of the robot, a second arm articulated at the opposite end of the first arm, and an R axis to operate. And an R-axis rotatably mounted at the free end to be rotatable. In addition to the three articulated axes, the base can be moved perpendicular to the robot arm, which is typically configured with three or four axes. Conventional SCARA robots are generally operated by a servo motor as a driving source.

The servomotor is generally large in size, and therefore the control device is also required to be large. Thus, the Scara robot has a fairly large volume that consumes very large power. The servomotor is also mounted vertically to the arm side of the robot. Thus, the SCARA robot must be robust and robust enough to support a large and heavy servomotor, and a large size control device is required to supply power to the servomotor. This is because the Scara robot is bulky.

In place of the servomotor, a stepping motor can be used to reduce the size of the Scara robot. However, if a positional firm action is not provided, in the first step of the control routine to control the stepping amount of the stepping motor in each moving step, that is, to control the moving amount of the stepping motor based on a reference position. It is always required to return to the initial set.

In addition, the SCARA robot driven by the AC servomotor is designed to automatically operate within a predetermined execution region of each person or some obstacle that may occur within the execution region. This will damage things or hurt people. Therefore, it is often required to mark "no access".

The present invention is provided to eliminate the drawbacks and disadvantages of the prior art, and it is a main object of the present invention to provide a mechanically compact and small sized Scara robot.

Another object of the present invention is to provide a stepping motor for driving the basic elements of the robot.

It is still another object of the present invention to provide a sensor for detecting the movement amount of the stepping motor, so that it is not necessary to return to the initial set in the first step of the control routine of the stepping motor in each movement step, thus the basic elements of the robot Is to ensure the correct movement.

Another object of the present invention is to correct the error by comparing the required amount of movement with the actual amount of movement of the stepping motor, thus ensuring the correct movement of the basic elements of the robot.

Another object of the invention is to stop the stepping motor if the error is detected in the stepping motion of the stepping motor.

Another object of the present invention is to display an error detected in the stepping motion of the stepping motor.

It is a further object of the present invention to provide a means for driving the stepping motor at reduced power to ascertain whether the basic elements of the robot are operated within a given area of execution.

In order to realize the above object of the present invention, a Scara robot has a robot body, a base installed on the robot body, and one end operatively connected to the base such that the first arm can move rotatably in a horizontal plane. A second arm having a first arm and one end operatively connected to an opposite end of the first arm so that the second arm can rotatably move in a horizontal plane, and R rotatably mounted to a free end of the second arm And a shaft, the scalar robot basically comprises a first stepping motor mounted on the base to move the first arm, a second stepping motor mounted on the base to move the second arm, and stepping of the stepping motor. Sensor means for detecting a quantity and means actuated in response to a signal from said sensor means; Thus, the position of each of the first and second arms is detected.

Hereinafter, the present invention will be described with reference to the accompanying drawings. In FIG. 1, the robot has a robot body 60 and a base 53 mounted to the robot body such that the base can be moved perpendicular to the robot body. The first arm 50 has one end operatively connected to the base 53 such that the first arm 50 can be rotatably moved in the base of the horizontal plane. The second arm 51 has one end operatively connected to the opposite end of the first arm 50 such that the second arm 51 can rotatably move on the first arm in the horizontal plane. The R axis is rotatably mounted to the free end of the second arm 51. The R axis is rotatably operated to substantially work. The flexible casing 61 extends between the robot body 60 and the base 53 to accommodate the connection of the robot.

A stepping motor 42 is installed on the robot body 60 to move the base 53 vertically of the robot body 60. Another stepping motor 12 is mounted to the base 53 and is operatively connected to the first arm 50 via a reduction device 15 such that the stepping motor 12 is in the horizontal plane of the base 53. It is driven to rotatably move the first arm.

Another stepping motor 22 is mounted to the base 53 and is operatively connected to the second arm 51 via a delivery device comprising a transfer belt, whereby the stepping motor 22 is connected to the first arm 50. Is driven to rotatably move the second arm 22 in the horizontal plane. Another stepping motor 32 is mounted to the base 53 and is operably connected to the R shaft 52 via a transmission device including a transmission belt, whereby the stepping motor 32 is connected to the R shaft 52. Driven to rotate.

With the mechanical arrangement as described above, as shown in FIG. 2, the robot has a drive mechanism 10 to move the first arm 50 as described above, and the second arm 51 as described above. ), Another drive mechanism 30 for rotating the R-axis 52 as described above, and another drive mechanism for moving the base 53, as described above. In order to control the operation of the basic elements of the robot, including mechanism 40, it is provided with a CPU1 operative to respond to signals or commands from RAM2, RAM3 and / or memory card 4; do. The drive mechanism 10 includes a drive motor control device 11 operated in response to a command from CPU1 to drive the stepping motor 12, thereby moving the first arm 50 to a predetermined distance. . The stepping motion of the stepping motor 12 is detected by the encoder 13 and fed back to the CPU1. An initial set of sensors 14 is installed to detect whether the stepping motor 12 is set to an initial position.

The other drive mechanisms 20, 30 and 40 are the same as the drive mechanism 10 for the components contained therein, although all are indicated with different reference numerals for each other.

The operation will be described with reference to FIG.

When power is supplied, the stepping motor is initialized (step S1). The operator inputs the information for the moving point (step S2) and gives an instruction for starting (step S3). The CPU1 is operated in response to initiating an instruction to calculate the stepping amount of the stepping motor to give commands to the stepping motors 12, 22, 32 and 42, respectively. The stepping motors 12, 22, 32 and 42 are driven in accordance with an instruction from the CPU1 (step S5). The encoders 3, 23, 33, and 43 are started to calculate the stepping pulses of the stepping motors 12, 22, 32, and 42, respectively (step S6), and feed back the calculated value to the CPU1 (step S6). ). The CUP1 compares the predetermined number of stepping pulses with the actual number of pulses (step S7). If the compared numbers are not equal to each other, the error is corrected (step S8) and the stepping motor is driven to the corrected value (step S5). On the other hand, if the compared numbers are the same, the next moving point is indicated (step S9). The operation from step S4 to step S9 is repeated until the stepping motor reaches the last target point (step S10).

Therefore, according to the present invention, during the stepping motion of the stepping motor, if an error is found, it is corrected to drive the stepping motor normally, so that high precision robot control is possible. In addition, the first step S1 need not be returned to correct the error each time an error is detected.

4 and 5 show a second embodiment of the present invention, wherein the error detection device 5, the stop device 6 and the display device 7 are the first of the present invention as shown in FIG. In addition to the examples provided. The error detection device 5 is designed to compare the required number of stepping pulses with the actual number of stepping pulses. If the compared numbers are not equal to each other, the error detection device 5 gives an error signal to CPU1 and then operates the stop device 6 to stop the stepping motors 12, 22, 32 and 42. do. At the same time, the display device 7 is operated to indicate an error by means of optical or voice recognition means. The other operation of the second embodiment is the same as that of the first embodiment.

According to the second embodiment of the present invention, if several obstacles are generated within a predetermined execution region of the robot, the basic element of the robot generates an error in the stepping motion of the stepping motor, so that the robot does not continuously operate. The stepping motor is stopped and an error is displayed at the same time.

FIG. 7 shows a third embodiment of the present invention, wherein a confirmation device 8 is additionally installed in the second embodiment of the present invention as shown in FIGS. 4 and 5. In the third embodiment, the confirmation device 8 is installed for operating the robot in a safe confirmation mode. In this case, the operator inputs the information in step S43, so that the drive motors 12, 22, 32, and 42 will be driven with reduced power in the predetermined area. With this reduced force the motor is driven at reduced torque and reduced speed. Other operations are the same as in the second embodiment of the present invention. By operating the robot in a safe confirmation mode before substantially operating the robot, the operator can know whether the robot is operating normally to ensure safety.

As described above, the present invention SCARA robot can suppress the danger when an obstacle or a person is within the operating range, can prevent malfunctions at this time, can recognize whether it can be safely operated or impossible before the actual driving operation and obstacles If so, appropriate obstacles can be handled.

Claims (11)

A robot body, a first arm rotatable in the horizontal plane, a second arm with one end connected to one end of the first arm so as to be rotatable in the horizontal plane, and a rotatable end in the free end of the second arm A scara robot having an R axis, the robot comprising: a; A base provided to drive in the vertical direction of the robot body to support the other end of the first arm so that the first arm can rotate in a horizontal plane; A first stepping motor mounted to the base for driving the first arm, A second stepping motor mounted to the base for driving the second arm, A third stepping motor mounted to the robot body to drive the base; A controller that calculates a required stepping amount and provides a stepping amount for the stepping motors, A sensor directly connected with the stepping motor to detect the actual stepping amount the stepping motor is substantially moved; Has detection means operated in response to a signal from the sensor to detect respective positions of the first and second arms, And said controller controls to drive said stepping motors such that said substantially moved stepping amount is equal to said required stepping amount. A robot body, a first arm rotatable in the horizontal plane, a second arm with one end connected to one end of the first arm so as to be rotatable in the horizontal plane, and a rotatable end in the free end of the second arm A scara robot having an R axis, the robot comprising: a; A base provided to drive in the vertical direction of the robot body to support the other end of the first arm so that the first arm can rotate in a horizontal plane; A first stepping motor mounted to the base for driving the first arm, A second stepping motor mounted to the base for driving the second arm, A third stepping motor mounted to the robot body to drive the base; A controller that calculates a required stepping amount and provides a stepping amount for the stepping motors, A sensor directly connected with the stepping motor to detect the actual stepping amount the stepping motor is substantially moved; Has detection means operated in response to a signal from the sensor to detect respective positions of the first and second arms, Determining whether the stepping motors are driven correctly by comparing the stepping amount supplied and the stepping amount supplied based on the stepping amount supplied to the stepping motor and the stepping amount actually moved from the sensor directly connected to the stepping motor. Scara robot having a device. delete The method according to claim 1 or 2, And a fourth stepping motor installed on the base and another sensor mounted on the base for detecting the stepping amount of the fourth stepping motor to rotate the R axis. 3. The SCARA robot according to claim 2, wherein said detecting means further has a stop means for stopping said drive source when detecting the error between the actual stepping amount and the required stepping amount of the stepping motors. 3. The SCARA robot according to claim 2, wherein said detecting means further has display means for displaying an error when detecting an error between an actual stepping amount and a required stepping amount of the stepping motor. A robot body, a first arm having one end connected to the robot body so that the first arm can rotate in the horizontal plane, a second arm having one end connected to the opposite end of the first arm so that the second arm can rotate in the horizontal plane, and A scara robot having an R axis rotatably installed at a free end of the second arm, the robot comprising: a robot; A first stepping motor for driving the first arm, a second stepping motor for driving the second arm, A sensor for detecting the stepping amount of the stepping motors; Deceleration means operated to drive the stepping motor at a lower force than a normal force; And having a judging device comparing the actual stepping amount of the stepping motors with the required stepping amount based on the signal from the sensor, thereby determining whether at least the stepping motors were driven correctly when moving at a low force. robot. 8. A scalar robot according to claim 7, further comprising means for setting an operating range in which the first arm and the second arm move at the low force. 9. The scalar according to any one of claims 7 to 8, wherein said detecting means further has display means for displaying an error when detecting an error between an actual stepping amount and a required stepping amount of the stepping motor. robot. 9. The scara robot of claim 7 or 8, wherein the sensor is directly connected to the stepping motor to detect an actual stepping amount of movement of the stepping motor. 9. A method according to any one of claims 7 to 8, characterized in that the detection means further has a stop device for stopping the stepping motor when it detects an error between the actual stepping amount and the required stepping amount of the stepping motors. Scara robot.

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