JP3187999B2 - Industrial robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot, and more particularly to an industrial robot for tracking and capturing a moving object with a robot hand.

[0002]

2. Description of the Related Art At present, an industrial robot used in a production line of a factory or the like performs an operation following components placed on a conveyor.

In this type of industrial robot, as shown in FIG. 5, a transfer conveyor 1 moving at a constant route and at a constant speed is used.
01 is placed on the robot 10
3 is taken by a CCD camera 104 provided at a fixed position above, and the moving speed of the object 102 is obtained based on the video information.
Is controlled to follow the object 102.

[0004]

However, in order to calculate the moving speed of the object 102, the conventional industrial robot needs a peripheral circuit 105 for image-processing an output from a solid-state image sensor such as a CCD. At the same time, it is necessary to provide the robot hand 106 with a proximity sensor for confirming and capturing the position of the target object 102.

Therefore, in the conventional apparatus, the position of the object is detected,
In addition, the circuit configuration for calculating the moving speed becomes complicated, and an increase in the size of the entire apparatus cannot be avoided.

The present invention has been made in view of the above problems, and has as its object to provide an industrial robot having a simple circuit for detecting the position of an object and calculating a moving speed. And

[0007]

SUMMARY OF THE INVENTION The present invention provides a method for providing a fixed path,
And a robot hand that captures an object moving at a speed, an arm having the hand at its tip and connected via a joint, and a trajectory of the arm so that the hand moves over an area above the path. An arm drive circuit for controlling
A sensor provided on the hand, for detecting that the target object is located in a hanging area of the hand, a timer for measuring a detection time of the sensor, and a control unit, wherein the control unit includes: Controls the arm drive circuit so that the object moves at a different moving speed with respect to the object and passes through the upper region of the object, and based on the moving speed of the hand and the output of the timer, the moving speed of the object. Is calculated.

[0008]

According to the present invention, it is possible to calculate the moving speed in addition to detecting the position of the object by using the sensor for detecting that the object is located in the hanging area of the robot hand.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described below.

FIG. 1 is a schematic perspective view showing the configuration of the industrial robot of the present invention.

In FIG. 1, reference numeral 1 denotes an object to be gripped placed on a conveyor 2 which moves at a constant route and speed. Reference numeral 3 denotes an industrial robot for capturing the target 1, which comprises an articulated arm 4 and a two-fingered robot hand 5. Reference numerals 6 and 7 denote first and second proximity sensors respectively provided at the two finger tips of the robot hand 5, and an object 1 moving on the conveyor 2 is a first and a second proximity sensor.
It detects that it is located in the hanging area of the proximity sensors 6 and 7.

Here, the robot hand 5 has first and second
The arrangement of the proximity sensors 6 and 7 is always located in a direction parallel to the moving direction of the conveyor 2.

Next, the circuit configuration of the industrial robot 3 of the present invention will be described with reference to the block diagram of FIG.

In FIG. 2, reference numeral 21 denotes the first proximity sensor 6,
A timer for measuring the detection time of the second proximity sensor 7, 22
Is a control unit for controlling the entire industrial robot 3,
In accordance with a program stored in the ROM 23 in advance, a control command is output to each section of the robot to calculate the moving speed of the object 1 and execute overall control. 24 is the control unit 2
The arm drive circuit outputs a drive signal to the arm motor 25 in accordance with a command from the arm 2. Move. Reference numeral 26 denotes a hand drive circuit that outputs a drive signal to a hand motor 27 in accordance with a command from the control unit 22.
Is performed. Reference numeral 28 denotes a RAM for storing the count time of the timer 21, the moving speed of the arm 4 driven by the arm motor 25, and the calculated moving speed of the object 1.

Next, the basic operation of the industrial robot 3 having the above configuration will be described with reference to the flowcharts of FIGS.

First, the movement acceleration a of the arm 4 is set to 0 as an initial value setting (S1).

Next, whether the first proximity sensor 6 and the second proximity sensor 7 that are turned on when the object 1 that moves on the conveyor 2 is located in the hanging area are turned off after being turned on, that is, Then, it is determined whether or not the object to be grasped 1 has passed through the hanging area of the robot hand 5 (S3). If NO, this operation is performed again, and if YES, the process proceeds to the next step S5.

In step S5, the moving direction of the arm 4 is determined based on the ON timing of the first proximity sensor 6 and the second proximity sensor 7, and the process proceeds to the next step S7. That is, the moving direction of the object 1 by the transport conveyor 2 is set to the first direction.
Detection is performed based on the ON timing of the proximity sensor 6 and the second proximity sensor 7, and the moving direction of the arm 4 is set to the same direction as the moving direction of the conveyor 2.

In step S7, 1 is set as the movement acceleration a.
m / s ² is added, and the process proceeds to the next step S9.

In step S9, the arm 4 is moved at a moving acceleration a by driving the arm motor 25, and the process proceeds to the next step S11, where the first proximity sensor 6 and the second proximity sensor 7 are both turned on. It is determined whether or not the target 1 is located in the hanging area of the first and second proximity sensors 6 and 7.

In step S11, if NO, the process returns to step S7, and if YES, step S13
Proceed to.

In step S13, the arm motor 25
Change the drive to move the acceleration a of the arm 4 is 0, the arm 4 is constant speed movement by the movement speed V _a1 at this time, and stores the moving speed V _a1 to RAM 28.

Then, counting is started by the timer 21 (S15), and the process proceeds to the next step S17. In this case, the moving velocity V _o of the moving speed V _a1 of the arm 4 object 1
Since the speed is faster, the robot hand 5 passes through the area above the object 1 after a predetermined time.

Therefore, in step S17, whether the first proximity sensor 6 and the second proximity sensor 7 are both turned off, that is, the object 1 is located in the hanging region of the first and second proximity sensors 6, 7 Determine if not.

In step S17, if NO, this operation is performed again, and if YES, step S19
Then, the counting by the timer 23 is terminated, and the count time T ₁ is stored in the RAM 28.

In the next step S21, 1 m / s ² is subtracted as the moving acceleration a, and the process proceeds to the next step S23.
The arm 4 is moved at the moving speed V by driving the arm motor 25.
Move from _a1 at a movement acceleration a.

In the next step S25, it is determined whether or not both the first proximity sensor 6 and the second proximity sensor 7 are turned on, that is, the object 1 is located in the hanging area of the first and second proximity sensors 6, 7. Determine if it is located.

In step S25, if NO, the process returns to step S21, and if YES, step S2
Go to 7.

In step S27, the arm motor 25
Change the drive to move the acceleration a of the arm 4 is 0, the arm 4 is constant speed movement by the movement speed V _a2 at this time, and stores the moving speed V _a2 to RAM 28.

Then, counting is started by the timer 21 (S29), and the process proceeds to the next step S31. In this case, the moving velocity V _o of the moving speed V _a2 of the arm 4 object 1
Since it is later, the target object 1 passes through the hanging area of the robot hand 5 after a predetermined time.

Therefore, in step S31, whether the first proximity sensor 6 and the second proximity sensor 7 are both turned off, that is, the object 1 has passed through the hanging regions of the first and second proximity sensors 6, 7 Determine whether or not.

In step S31, if NO, this operation is performed again, and if YES, step S33
The process proceeds to store the count time T ₂ ends the counting by the timer 21 to the RAM 28.

Then, in the next step S35, the RAM
Moving speed stored in the 28 V _a1, V _a2, and the count time T _1, T ₂ from the moving speed V _o of the object 1 is calculated based on the following equation, and stores the calculation result in the RAM 28. This is because the arm 4 has a relative speed (V _a1 −
V _o ), passes the object 1 at time T ₁ , and
There is utilized to pass through the object 1 at time T ₂ to the object 1 at a relative velocity (V _a2 -V _o).

[0034]

(Equation 1)

Next, 1 m / s ² is added as the moving acceleration a (S37), and the flow advances to the next step S39.

In step S39, the arm 4 is moved from the moving speed _Va2 to the moving acceleration a by the driving of the arm motor 25.
It is determined whether both the proximity sensor 6 and the second proximity sensor 7 have been turned on, that is, whether the object 1 is located in the hanging area of the first and second proximity sensors 6 and 7.

In step S41, if NO, the process returns to step S37, and if YES, step S4
Proceed to 3.

In step S43, the movement of the arm 4 is R
AM28 such that the constant speed movement of the stored moving speed V _o to, change the drive of the arm motor 25 proceeds to the next step S45. Thereby, the robot hand 5 moves the object 1 so that the object 1 is always located in the hanging area.
Follow-up movement of the upper part of.

In step S45, the first proximity sensor 6,
Then, the hand motor 27 is driven based on the output of the second proximity sensor 7, and the opening / closing degree of the robot hand 5 is adjusted to hold the object 1.

As described above, the detection of the moving speed of the object 1
And all the operations of the capture are ended.

In the above embodiment, the moving speed of the object 1 is calculated based on the outputs of the first proximity sensor 6, the second proximity sensor 7, and the timer 21, but the moving direction of the conveyor 2 is predetermined. In this case, it can be calculated based on one of the sensor outputs.

[0042]

As described above, according to the present invention, it is possible to calculate the moving speed in addition to detecting the position of the object by using the sensor for detecting that the object is located in the hanging area of the robot hand. Therefore, there is no need for a peripheral circuit for processing the output of a solid-state imaging device such as a CCD as in the related art, and the circuit for detecting the position of the object and calculating the moving speed has a simple configuration. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a configuration of an industrial robot of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of the industrial robot of the present invention.

FIG. 3 is a flowchart for explaining a basic operation of the industrial robot of the present invention.

FIG. 4 is a flowchart for explaining a basic operation of the industrial robot of the present invention.

FIG. 5 is a schematic perspective view showing a configuration of a conventional industrial robot.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Grasp target 2 Conveyor 3 Industrial robot 4 Arm 5 Robot hand 6 1st proximity sensor 7 2nd proximity sensor 21 Timer 22 Control part 23 ROM 24 Arm drive circuit 25 Arm motor 26 Hand drive circuit 27 Hand motor 28 RAM

Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B25J 3/00-3/10 B25J 9/10-9/22 B25J 13/00-13/08 B25J 19/02-19 / 06 G05B 19/18-19/46

Claims (1)

(57) [Claims] 1. A robot hand for catching an object moving at a constant path and speed, an arm having the hand at its tip and connected via a joint, and the hand extending over an area above the path. An arm drive circuit for controlling the trajectory of the arm so as to move; a sensor provided in the hand, for detecting that the object is located in a hanging area of the hand; and measuring a detection time of the sensor. A timer; and a control unit, wherein the control unit controls the arm driving circuit so that the hand moves at a different speed with respect to the target object and passes through an upper region of the target object. An industrial robot that calculates a moving speed of an object based on a moving speed of the hand and an output of the timer.