TWI446305B - Robot teaching device and teaching method thereof - Google Patents

Description

Mechanical arm teaching device and teaching method thereof

The present invention relates to a teaching apparatus and method thereof, and more particularly to a teaching apparatus for rapidly teaching a robot arm of a robot arm by using a least square approximation method and a reverse kinematics to generate teaching materials and teaching methods thereof. .

In recent years, with the vigorous development of institutional science, automation control and computer technology, the robotic arm has been widely used in various industries, which can provide high efficiency and stable automated production and assembly.

In general, most of the robotic arm is still used in fixed work that requires repeated processing, such as: assembly, processing, welding, cutting, pressurizing, handling, testing, etc. In this case, after the work needs to be planned, the teacher is used to teach the robot arm to move and rotate along a fixed trajectory, so that the robot can repeatedly process the above fixed work. Since in conventional teachers, movement can only be controlled in a single axial direction at a time, teaching efficiency is low and accuracy is poor.

In view of this, it has been proposed to use laser light to detect the target to improve accuracy. However, the above method will add additional costs, such as the need for a laser source and components for detecting laser light. In addition, since laser light is used in this way, it is necessary to consider whether the laser light will be shielded, and whether the laser light will affect the robot arm or the like. Therefore, although the above method improves the accuracy of the robot arm, it also causes the structure of the teacher to be complicated and costly, and may instead cause the teaching efficiency to be low due to the need to consider the influence of the laser light on the robot arm, so the above method still cannot effectively solve the teaching. The problem of poor efficiency.

In summary, it can be seen that the teaching of the robot arm has existed for a long time in the prior art. The problem of poor efficiency and accuracy, it is necessary to propose improved technical means to solve this problem.

In view of the problems of the prior art, the present invention discloses a teaching apparatus of a robot arm and a teaching method thereof.

The teaching device of the robot arm disclosed by the invention comprises: a teaching pen, a three-dimensional coordinate position picker, a calculation module and a generating module. Wherein, the teaching pen is arranged on the mechanical arm, the teaching pen has a pen tip; the three-dimensional coordinate position picker is used to set the sensing point on the teaching pen, and capture and record the coordinates of each sensing point in the teaching state; The group is used to calculate the three-dimensional coordinate point of the pen tip according to the coordinates of each sensing point by the least square approximation (LSA), and calculate the rotation amount of the pen according to the inverse kinematics (IK); The teaching data is generated according to the calculated three-dimensional coordinate point and the rotation amount, so that the robot arm moves and rotates according to the teaching material after the teaching is completed.

As for the teaching method of the robot arm disclosed in the present invention, the steps include: setting the teaching pen to the robot arm, and the teaching pen has a pen tip; setting a sensing point on the teaching pen, and capturing and recording each in the teaching state a coordinate of a sensing point; calculating a three-dimensional coordinate point of the pen tip according to a coordinate of each sensing point by a least square approximation method; teaching the rotation amount of the pen according to the inverse kinematics calculation; generating teaching materials according to the calculated three-dimensional coordinate point and the rotation amount, The robotic arm is moved and rotated according to the teaching material after the teaching is completed.

The device and method of the present invention are as above, and the difference from the prior art is that the present invention is to provide a teaching pen having a sensing point on the robot arm, and to extract coordinates of the sensing point so as to minimize the coordinate according to the captured coordinates. Square approximation calculation The three-dimensional coordinate point of the pen tip of the pen and the amount of rotation of the pen are taught according to the inverse kinematics calculation, and the teaching material is generated according to the three-dimensional coordinate point and the rotation amount, so that the robot arm moves and rotates according to the teaching material after the teaching is completed.

Through the above technical means, the present invention can achieve the technical effect of improving the teaching efficiency of the robot arm.

The embodiments of the present invention will be described in detail below with reference to the drawings and embodiments, so that the application of the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented.

First, before explaining the teaching device of the robot arm of the present invention and the teaching method thereof, the application environment of the device will be described. The device is disposed at the operating end of the robot arm, such as a jig. After that, the robot is quickly taught by the operator to directly control the teaching pen to complete various tasks, such as industrial operation or art drawing.

Next, for the description of the nouns defined by the present invention, the teaching pen of the present invention refers to a pen-like teaching element which can assume a "y" shape and is provided with a sensing point on the teaching pen to provide a three-dimensional coordinate position. The picker takes its coordinates and calculates the three-dimensional coordinate point of the pen tip of the teaching pen and the amount of rotation thereof. Since the coordinates of the sensing point are known as conventional techniques, no further details are provided herein.

Next, the teaching device of the robot arm of the present invention will be described first. Please refer to FIG. 1 and FIG. 1 is a block diagram of the teaching device of the robot arm of the present invention, including: teaching pen 10, three-dimensional coordinate position 撷The extractor 20, the calculation module 30 and the generation module 40 are provided. Among them, the teaching pen 10 is used to be disposed on a robot arm, and the teaching pen has a pen tip.

The three-dimensional coordinate position picker 20 is used to set the sensing points on the teaching pen, and to capture and record the coordinates of each sensing point while teaching the state. In actual implementation, the sensing points are at least three, and the sensing points are set at different positions, and in order to improve the accuracy, the distance between the sensing points may be more than three centimeters. In addition, the three-dimensional coordinate position extractor 20 can also record the calculation position of the teaching pen 30 in the three-dimensional space and the amount of rotation. In particular, the higher the measurement accuracy of the three-dimensional coordinate position extractor 20 and the faster the sampling frequency, the higher the accuracy of the robot arm.

The calculation module 30 is configured to calculate the three-dimensional coordinate point of the pen tip according to the coordinates of each sensing point by a least square approximation method, and to teach the rotation amount of the pen according to the inverse kinematics calculation. The least square approximation method is a method for calculating the closest value of each value in the coordinate axis in the numerical method. In practical implementation, it can be used to calculate the three-dimensional coordinate point of the pen tip of the teaching pen. In addition, the inverse kinematics is to calculate the amount of rotation of the shaft joint by the position of the known end of the robot arm in three-dimensional space. In particular, the computing module 30 stores the initial state of the teaching pen, which includes the coordinates of each sensing point. Since the least square approximation method and the inverse kinematics are well-known techniques, they will not be repeated here.

The generating module 40 is configured to generate teaching materials according to the three-dimensional coordinate points and the rotating amount calculated by the computing module 30. In practical implementation, the teaching materials can be input to the robot arm and the encoded data that can be recognized by the robot arm. It is used to move and rotate the robot arm according to the teaching materials after the teaching is completed. In addition to coding the teaching materials, encryption processing can be performed to improve the safety of the robot arm. However, after the teaching materials are encrypted, the control end of the robot arm needs to have a corresponding decryption process. In this way, the robotic arm can operate in accordance with the taught trajectory path. Because the robot arm moves and rotates according to the teaching materials, it is known Technology, so I won't go into details here.

As shown in FIG. 2, FIG. 2 is a flowchart of a method for teaching a robot arm of the present invention, the steps of which include: setting a teaching pen to a robot arm, and the teaching pen has a pen tip (step 210); A sensing point is set on the teaching pen, and the coordinates of each sensing point are captured and recorded in the teaching state (step 220); the three-dimensional coordinate point of the pen tip is calculated according to the coordinates of each sensing point by a least square approximation (step 230) The rotation amount of the pen is taught according to the inverse kinematics calculation (step 240); the teaching material is generated according to the calculated three-dimensional coordinate point and the rotation amount, so that the robot arm moves and rotates according to the teaching material after the teaching is completed (step 250). By the above steps, a teaching pen having a sensing point is disposed on the robot arm, and coordinates of the sensing point are extracted, so that the three-dimensional coordinate point of the pen tip of the teaching pen is calculated according to the extracted coordinates in a least square approximation, and according to the reverse direction The kinematic calculation teaches the amount of rotation of the pen, and generates teaching materials based on the three-dimensional coordinate points and the amount of rotation, so that the robot arm moves and rotates according to the teaching material after the teaching is completed.

Please refer to "Fig. 3", which is a schematic diagram of a teaching pen and a sensing point thereof to which the present invention is applied, which includes a teaching pen 300, sensing points (301 to 303), and a pen tip 304. As mentioned above, in actual implementation, each sensing point (301~303) is disposed at different positions of the teaching pen 300, and in order to improve the accuracy, the distance between the sensing points (301~303) is at least three centimeters, That is, the distance between the sensing point 301 and the sensing point 302 is greater than or equal to three centimeters; the distance between the sensing point 302 and the sensing point 303 is also greater than or equal to three centimeters; the distance between the sensing point 301 and the sensing point 303 is also greater than or equal to Three centimeters. In this way, the calculation module 30 can accurately calculate the three-dimensional coordinate point of the nib 304 according to the coordinates of each sensing point (301-303) in a least square approximation, and use the inverse kinematics calculation to teach the rotation amount of the pen 300.

As described above, although the present invention is exemplified by three sensing points, the present invention is not limited thereto. In other words, in practice, more than three sensing points can be set on the teaching pen 300. As long as the respective sensing points are located at different positions of the teaching pen 300, in order to improve the accuracy, it is also recommended to maintain the distance between the sensing points to be more than three centimeters.

In summary, it can be seen that the difference between the present invention and the prior art is that a teaching pen having a sensing point is disposed on the robot arm, and coordinates of the sensing point are extracted, so that the teaching pen is calculated by the least square approximation method according to the extracted coordinates. The three-dimensional coordinate point of the nib, and the amount of rotation of the pen according to the inverse kinematics calculation, and the teaching data is generated according to the three-dimensional coordinate point and the rotation amount, so that the robot arm moves and rotates according to the teaching material after the teaching is completed, thereby The technical means can solve the problems existing in the prior art and achieve the technical effect of improving the teaching efficiency of the robot arm.

While the present invention has been described above in the foregoing embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of patent protection shall be subject to the definition of the scope of the patent application attached to this specification.

10‧‧‧Teaching pen

20‧‧‧3D coordinate position picker

30‧‧‧Computation Module

40‧‧‧Generation module

300‧‧‧Teaching pen

301~303‧‧‧Feeling point

304‧‧‧ nib

Step 210‧‧‧Set a teaching pen on the robot arm, and the teaching pen has a tip

Step 220‧‧‧ Set at least three sensing points on the teaching pen, and capture and record the coordinates of each sensing point while teaching the state

Step 230‧‧‧ Calculate a three-dimensional coordinate point of the nib by the least square approximation according to the coordinates of each sensing point

Step 240‧‧‧ Calculate the amount of rotation of the teaching pen based on inverse kinematics

Step 250‧‧‧ generates a teaching material according to the calculated three-dimensional coordinate point and the rotation amount, so that the robot arm moves and rotates according to the teaching material after the teaching is completed

Figure 1 is a block diagram of the teaching device of the robot arm of the present invention.

2 is a flow chart of a method of teaching a robot arm of the present invention.

Figure 3 is a schematic diagram of the teaching pen and its sensing points to which the present invention is applied.

10‧‧‧Teaching pen

20‧‧‧3D coordinate position picker

30‧‧‧Computation Module

40‧‧‧Generation module

Claims (8)

A teaching device for a robot arm, comprising: a teaching pen for being disposed on a robot arm, the teaching pen having a tip; a three-dimensional coordinate position picker for setting at least three sensing points on the teaching pen, And capturing and recording the coordinates of each sensing point while teaching the state; a computing module for calculating a three-dimensional coordinate point of the nib according to the coordinates of each sensing point by a least square approximation, and calculating according to inverse kinematics And a generating module, configured to generate a teaching material according to the calculated three-dimensional coordinate point and the rotation amount, so that the robot arm moves and rotates according to the teaching material after the teaching is completed. The teaching device of the robot arm according to claim 1, wherein the sensing points are respectively at different positions of the teaching pen, and the distance between the sensing points is at least three centimeters. The teaching device of the robot arm of claim 1, wherein the computing module stores an initial state of the teaching pen. The teaching device of the robot arm according to claim 1, wherein the three-dimensional coordinate position picker records a moving position and a rotation amount of the teaching pen in a three-dimensional space. The teaching device of the robot arm of claim 1, wherein the teaching material is encoded and encrypted by an encoder. A teaching method of a robot arm, the method comprising: setting a teaching pen on a robot arm, and the teaching pen has a tip; setting at least three sensing points on the teaching pen, and in the teaching state Taking a coordinate of each sensing point; calculating a three-dimensional coordinate point of the pen tip according to a coordinate of each sensing point; calculating a rotation amount of the teaching pen according to inverse kinematics; and calculating the The three-dimensional coordinate point and the amount of rotation generate a teaching material that causes the robotic arm to move and rotate according to the teaching material after the teaching is completed. The teaching method of the robot arm according to claim 6, wherein the sensing points are respectively at different positions of the teaching pen, and the distance between the sensing points is at least three centimeters. The teaching method of the robot arm of claim 6, wherein the teaching material is encoded and encrypted by an encoder.