CN106610267A - Robot joint zero-point automatic calibration end performing device, and method thereof - Google Patents

Abstract

The invention discloses a robot joint zero-point automatic calibration end performing device, and the device comprises a mechanical arm disposed on a robot body, and an external positioning ball. The mechanical arm consists of three laser distance sensors which are perpendicular to each other. The three laser distance sensors are used for carrying out the automatic calibration of a robot joint through touching the surface of the positioning ball. The device is high in precision, is lossless, and is stable in long-time performance. An automatic calibration method is used for directly measuring the position and vector of each shaft, thereby avoiding the calculation and model errors, improving the control precision of a robot, and reducing the machining precision and cost of the robot.

Description

The automatic calibrating end performs device of joint of robot zero point and its method

Technical field

The present invention relates to robot automation's technical field, more particularly to a kind of joint of robot zero Point auto-calibration end performs device and its method.

Background technology

At present, all of machine Moral quality card, after robot is completed to before dispatching from the factory, Need to calibrate each joint of robot.However, traditional calibration steps is cumbersome And it is poorly efficient, traditional method is to carry out zero point school to each joint shaft one by one by a micrometer It is accurate.As shown in figure 1, when thimble touches the minimum point of V-groove, data are recorded, and Zero point is labeled as, V-groove is located on the circumference at joint of robot.By then passing through people's eyes The mode record data of survey can cause unavoidably error, it is difficult to ensure absolute reliability, and efficiency is low Under.Even with the micrometer of sensor type, although can automatically record V-groove minimum point, But need repeatedly can just complete each joint shaft installation unloading by artificial, still not to the utmost Such as people's will.

The content of the invention

In order to overcome drawbacks described above, the invention provides a kind of automatic school of joint of robot zero point Quasi- end performs device, and relative to traditional calibration steps, it is possible to increase calibration accuracy and control The precision of simulation, improves device person joint's zero point automatic calibrating method of the precision of robot.

The technical scheme that adopted to solve its technical problem of the present invention is：A kind of robot is closed The section automatic calibrating end performs device of zero point, including the mechanical gripper on robot body, And the place kick of outside, the mechanical gripper is by 3 mutually orthogonal vertical laser distances biographies Sensor is constituted, and 3 laser distance sensors are by contact positioned at the surface of place kick.

A kind of joint of robot zero point calibrated using device as claimed in claim 1 is certainly Dynamic calibration steps, comprises the following steps：

1) one angle [alpha] of first axle twice on rotary machine human body, and record handgrip institute The sphere centre coordinate P of the outside place kick for measuring₁、P₂And P₃；

2) P is drawn₁P₂And P₂P₃Perpendicular bisector, their intersection point is exactly the first of robot The center of rotation position P of axle_x1；

3) while, the axial vector Ax1 of first axle can pass through vector cross product P₁P₂×P₂P₃Meter Calculate result to obtain；

4) repeat the above steps, measure respectively the axial vector Axi of other each axles of robot body And its center of rotation coordinate P_xi, after obtaining the mutual distance of each center of rotation, that is, obtain The each interarticular length of robot, meanwhile, obtain each axial vector, that is, obtain each pass The relative position of internode.And it is exactly that robot is closed that these close panel length and the relative position in joint The data of section calibration, so as to accurately be calibrated.

The invention has the beneficial effects as follows：A kind of new non-contact laser sensor of the present invention Handgrip, it is lossless, long-term with high precision for carrying out the automatic calibration of joint of robot The features such as stable performance；And a kind of calibration steps of automatization, directly to the position of each axle Measure with vector, it is to avoid calculating and model error, improve the control accuracy of robot, Reduce the machining accuracy and cost of robot；

The calibration of typically now joint of robot axle is required for expending a large amount of manpowers, and the present invention is significantly Labour force is saved, the full-automation of calibration is realized, the productivity is improve.The present invention can also The precision of machine human operator model is improved, robot in actual use absolute is improve Precision.

Description of the drawings

Fig. 1 is each joint calibration steps schematic diagram of this existing robot；

Fig. 2 is the apparatus structure schematic diagram of the present invention；

Fig. 3 is the computational methods schematic diagram of the sphere centre coordinate P of outside place kick in the present invention；

Fig. 4 is each joint calibration steps schematic diagram of robot of the present invention；

Indicate in figure：1- robot bodies；2- mechanical grippers；3- place kick；4- laser distances Sensor.

Specific embodiment

In order to deepen the understanding of the present invention, below in conjunction with embodiment and accompanying drawing to present invention work It is described in further detail, the embodiment is only used for explaining the present invention, does not constitute to present invention protection model The restriction enclosed.

Fig. 2 shows a kind of automatic calibrating end performs device of joint of robot zero point of the invention A kind of embodiment, including the mechanical gripper 2 and outside being arranged on robot body 1 Place kick 3, the mechanical gripper 2 is by 3 mutually orthogonal vertical laser distance sensors 4 Composition, it is respectively laser distance sensor a, laser distance sensor b and laser distance sensing Device c, 3 laser distance sensors 4 are by contact positioned at the surface of place kick 3.

The joint of robot zero point automatic calibrating method that carrying out as shown in Figure 4 is calibrated, including with Lower step：

1) one angle [alpha] of first axle twice on rotary machine human body, and record handgrip institute The sphere centre coordinate P of the outside place kick for measuring₁、P₂And P₃；

As shown in figure 3, sphere centre coordinate P_n(n=1,2,3), broken line triangle in front view 3 vertex representations, 3 laser sensors project to the measurement point of sphere, because the radius of a ball is known as R, it is easy to try to achieve this 3 points circumradius r and the circle to the centre of sphere apart from d, and Sphere center position Pc.

2) P is drawn₁P₂And P₂P₃Perpendicular bisector, their intersection point is exactly the first of robot The center of rotation position P of axle_x1；

3) while, the axial vector Ax1 of first axle can pass through vector cross product P₁P₂×P₂P₃Meter Calculate result to obtain；

4) repeat the above steps, measure respectively the axial vector Axi of other each axles of robot body And its center of rotation coordinate P_xi, after obtaining the mutual distance of each center of rotation, that is, obtain The each interarticular length of robot, meanwhile, obtain each axial vector, that is, obtain each pass The relative position of internode.And it is exactly that robot is closed that these close panel length and the relative position in joint The data of section calibration, so as to accurately be calibrated.

Claims (2)

1. the automatic calibrating end performs device of a kind of joint of robot zero point, it is characterised in that：Bag Include the place kick (3) of mechanical gripper (2) on robot body (1) and outside, institute State mechanical gripper (2) to be made up of 3 mutually orthogonal vertical laser distance sensors (4), described 3 Individual laser distance sensor (4) is by contact positioned at the surface of place kick (3).

2. a kind of joint of robot zero point calibrated using device as claimed in claim 1 Automatic calibrating method, it is characterised in that comprise the following steps：

1) one angle [alpha] of first axle twice on rotary machine human body, and record handgrip institute The sphere centre coordinate P of the outside place kick for measuring₁、P₂And P₃；

2) P is drawn₁P₂And P₂P₃Perpendicular bisector, their intersection point is exactly the first of robot The center of rotation position P of axle_x1；

3) while, the axial vector Ax1 of first axle can pass through vector cross product P₁P₂×P₂P₃Meter Calculate result to obtain；

4) repeat the above steps, measure respectively the axial vector Axi of other each axles of robot body And its center of rotation coordinate P_xi, after obtaining the mutual distance of each center of rotation, that is, obtain The each interarticular length of robot, meanwhile, obtain each axial vector, that is, obtain each pass The relative position of internode.And it is exactly that robot is closed that these close panel length and the relative position in joint The data of section calibration, so as to accurately be calibrated.