CN109839087B - Portable rigid-flexible composite mechanism and robot performance testing method - Google Patents

Abstract

The invention discloses a portable rigid-flexible composite mechanism and a robot performance testing method. The testing method relates to a portable rigid-flexible composite mechanism and a robot performance testing device. The testing device includes a main bracket, a telescopic arm, and a slidable base. , Pull rope displacement sensor, target, pull rope and information processing panel, connect the target with the measured mechanism, start the measured mechanism, and the measured mechanism drives the target movement, thereby driving the rope length change of the rope displacement sensor, and the pull rope The displacement sensor records the rope length change data in real time, and sends the data to the information processing panel under the main support. The information processing panel simplifies the structure of the test device and establishes a three-dimensional mathematical model. Finally, the rope length change data is substituted to obtain the motion performance of the tested mechanism. parameter. The invention has a wide application range and can accurately calculate the movement position, movement track and movement speed of the parallel mechanism or the series mechanism under test.

Description

A portable rigid-flexible composite mechanism and robot performance testing method

technical field

The invention relates to the field of mechanics and robotics, in particular to a portable rigid-flexible composite mechanism and a performance testing method for a robot.

Background technique

With the rapid development of China's economy and the continuous improvement of the automation level of Chinese enterprises, the demand for institutions and the robot market is increasing, and there are more and more types.

Compared with the series mechanism, the parallel mechanism is an important research field of mechanics and robotics. It is a closed-loop mechanism that connects the moving platform and the fixed platform through multiple branches. Its characteristic is that each branch chain can accept the drive at the same time. The input together determines the output of the motion platform. The multi-closed-loop space kinematic chain of the parallel mechanism has increased stiffness, reduced accumulated error, better kinematic performance and more compact structure than the series mechanism. . In particular, it provides a new hot spot for the research of robots and machine tools, and makes up for the shortcomings of the series mechanism. Due to the high structural rigidity, strong bearing capacity and high position accuracy of the parallel mechanism, it has attracted domestic and foreign engineering and academic circles. For decades, people have been continuously working on the research and development of new parallel mechanisms.

At present, there are many types of parallel mechanisms and robots in my country, and the technology of each manufacturer is quite different. The performance indicators of the test standard are freely selected by the manufacturer. Different robots have different motion characteristics, large differences in stroke, speed, trajectory, and accuracy, and different requirements for testing equipment.

The current test tools include laser tracker, three-coordinate measuring instrument and other tools. The laser tracker has the function of tracking space motion, so as to meet the needs of space measurement, but it will cause a certain error in angle calculation and conversion, and the long distance will cause the error to be too large.

For example, a robot three-dimensional repetitive positioning test system disclosed in Patent 201710095556.7, the test system fixes three laser displacement sensors on three brackets in two orthogonal directions, and simultaneously projects three laser beams to the reflector, synchronizing 3D coordinate acquisition is performed. However, when the robot moves too fast, the laser displacement sensor cannot guarantee the tracking in place in time; and after there is rotation and angle inclination, since the sensor only has the displacement function and cannot be rotated, there is no way to ensure that the two are orthogonal, and the collected data may appear too large. deviation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a portable rigid-flexible composite mechanism and a robot performance testing method, which can accurately calculate the motion position, motion trajectory and motion speed of the tested parallel mechanism or series mechanism, and has a wide range of applications.

In order to achieve the above object, technical scheme of the present invention is as follows:

A portable rigid-flexible composite mechanism and a robot performance test method, the test method relates to a portable rigid-flexible composite mechanism and a robot performance test device, the test device includes a main support, a telescopic arm, a slidable base, and a pull rope displacement The sensor, the target, the pulling rope and the information processing panel, the main bracket is connected to the three telescopic arms respectively through the double-headed ball connecting rod, a slidable base is installed on each of the three telescopic arms, and the slidable base is slidably fixed on the telescopic arm, two of which are Two pull-rope displacement sensors are installed on each slidable base, and three pull-rope displacement sensors are installed on the other slidable base. There are nine locating pins at the connecting end, and three locating pins are inserted into each connecting end. One locating pin is arranged just above the connecting end, and the other two locating pins are respectively arranged on both sides of the connecting end. Correspondingly, on each telescopic arm Three positioning pins are also inserted, and the corresponding positioning pins are connected with buckles. When connecting, the main bracket and the telescopic arm are firmly and horizontally combined together. The connecting end of the main bracket is designed as an inwardly inclined slope. When open, the telescopic arm can rotate from horizontal downward to vertical state around the slope-shaped connecting end of the main bracket with the assistance of the double-headed ball connecting rod, the positioning pins on both sides and the buckle. The slidable base, the rope displacement sensor, and the target are disassembled separately; the main bracket is placed with an information processing panel, which is connected to the rope displacement sensor, and the information processing panel collects the change data of rope length, based on the change of rope length. data, the test method includes:

1) The structure of the test device is simplified: the position of the slidable base is set as three points ABC to form a triangle ABC, there are three designated positions on the target, and the three designated positions are set as the three points of DEF to form a triangle DEF, and then one of them can be slidable. The three pull ropes of the base are respectively connected to three designated positions, and the four pull ropes on the other two slidable bases are respectively connected to the three designated positions according to the ratio of 2:1:1. Connect the three points ABC and the three points DEF, that is, the lengths of the seven line segments AE, AD, AF, BE, BF, CF, and CD;

2) Re-simplification: The structure can be further divided into three triangular pyramids, namely triangular pyramid F-ABC, triangular pyramid E-FAB, triangular pyramid D-FAC, with point A as the coordinate origin, and the Z axis is perpendicular to the plane where the triangle ABC is located. Up, the straight line where AC is located is the direction of the Y-axis, and the direction of the X-axis is the vector cross product of the Z-axis and the Y-axis;

3) Parameter calculation: In the triangular pyramid F-ABC, the coordinates of the three points of the triangle ABC are known, and the lengths of the three edges are respectively l _FA , l _FB , l _FC , and the following equation can be established from the geometric relationship:

From this, the coordinates of point F can be obtained, that is, the three values of x _F , y _F , and z _F ; in the same way, the coordinates of two points D and E can be obtained, and then the coordinates of the middle point of the triangle DEF can be obtained, that is, the The movement position of the measuring mechanism;

Repeat the calculation of the collected rope length change data according to the above steps, and you can get all the point sets of the coordinates of the middle point of the triangle DEF, that is, the motion trajectory of the tested mechanism;

Based on the motion trajectory, and then converted with time, the motion speed of the tested mechanism can be obtained.

Preferably, the side lengths of the triangle DEF and the triangle ABC can be determined according to the designated position and the position of the slidable base in actual work, respectively.

Preferably, the movement speed is converted with time to obtain the movement acceleration of the measured mechanism.

After the above scheme is adopted, the measured mechanism drives the target of the present invention to move during movement, and the rope displacement sensor connected with the target through the rope can collect the change data of rope length in time, and feed it back to the information processing panel directly under the main support. , the information processing panel collects the change data of the rope length for use in the calculation of other performance parameters; in addition, the present invention can be widely used in most In the testing organization, it is very practical.

The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is the working flow chart of the present invention;

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

3 is a perspective view of the main support of the present invention;

Figure 4 is a perspective view of the telescopic arm of the present invention;

5 is a perspective view of a double-ended ball connecting rod of the present invention;

6 is a perspective view of the slidable base 1 of the present invention;

7 is a perspective view of the slidable base 2 of the present invention;

FIG. 8 is a folded perspective view of the main body of the present invention;

9 is a perspective view of the target of the present invention;

FIG. 10 is a working principle diagram of the present invention.

Label description

1-main bracket; 2-telescopic arm; 3-slidable base; 4-rope displacement sensor; 5-target; 6-rope; 7-positioning pin; 8-buckle; 9-step slot; 10-slide rail; 11-round slot; 12-ball slot; 13-information processing panel; 14-double-headed ball connecting rod; 15-buckle; 16-expandable rod; 17-groove; 19-designated position; 20-level.

specific embodiment

A portable rigid-flexible composite mechanism and robot performance testing device disclosed in the present invention, referring to Figures 1-10, includes a main support 1, a telescopic arm 2, a slidable base 3, a pull-rope displacement sensor 4, a target 5, a pull-rope 6 and information processing panel 13.

As shown in Figure 2, the main bracket 1 is connected to three telescopic arms 2 respectively, the main bracket 1 and the telescopic arm 2 are connected by a double-ended ball connecting rod 14, and the main bracket 1 and the telescopic arm 2 are provided with connecting grooves for the double-ended ball connecting rod 14 to connect , in order to cooperate with the double-headed ball connecting rod 14, a circular groove 11 is opened below the main bracket 1 and the telescopic arm 2, and a spherical groove 12 is opened at the end of the circular groove 11. The circular groove 11 and the spherical groove 12 together form a connecting groove. to place the double-ended ball connecting rod 14.

3, in this preferred embodiment, there are nine positioning pins 7 at the connecting end of the main bracket 1, three positioning pins 7 are inserted into each connecting end, one positioning pin 7 is set just above the connecting end, and the other two The positioning pins 7 are respectively arranged on both sides of the connecting end. Correspondingly, three positioning pins 7 are also inserted on each telescopic arm 2, and the corresponding positioning pins 7 are connected with buckles 8, which can ensure that the main support 1 and the telescopic arm are connected during the connection. The arms 2 are firmly combined together, and the connecting end of the main bracket 1 is designed as an inwardly inclined slope. If the buckle 8 directly above is released, the telescopic arm 2 is connected to the double-headed ball connecting rod 14, the positioning pins 7 on both sides and the buckle. With the aid of 8, the telescopic arm 2 can be rotated from the horizontal downward to the vertical state around the slope-shaped connecting end of the main bracket 1, as shown in FIG. 9 .

If the test device is not used, the slidable base 3, the pull-rope displacement sensor 4, and the target 5 can be disassembled separately, and the remaining telescopic arms can be folded as shown in Figure 9, and finally placed in the storage box, which is very convenient and convenient for storage. , portable, to overcome the problem of large space occupied by traditional test devices.

A slidable base 3 is installed on each of the three telescopic arms 2, and the telescopic arms 2 are provided with slide rails 10 and card slots 9;

The slidable base 3 is provided with a groove 17 that matches the slide rail 10 so that the slidable base 3 can slide back and forth on the telescopic arm 2. In order to optimize the structure, the two sides of the slidable base 3 are hollowed out for the telescopic arm 2 to be inserted. Grooves 17 are formed on both sides of the inside of the slidable base 3;

A buckle 15 that can move up and down is arranged above the slidable base 3, a telescopic rod 16 is arranged between the slidable base 3 and the buckle 15, and the slot 9 on the telescopic arm 2 is stepped; when the base needs to be moved , the telescopic rod 16 above the movable base 3 rises, and the buckle 15 is lifted up. After the base moves to the desired position, the telescopic rod 16 drives the buckle 15 to descend, and the buckle 15 and the ladder on the telescopic arm 2 are locked. The grooves 9 are fixed together, and this structure can fix the slidable base 3 and the pull-rope displacement sensor 4 to the required positions, preventing slippage during the working process and affecting the final test accuracy.

It should be noted that, as shown in Figure 4, the telescopic arm 2 has a telescopic function and can be adjusted according to actual needs.

The slidable base 3 is divided into two types, and the two shapes are roughly the same. The difference between the second type of slidable base and the first type is that three pull-rope displacement sensors 4 can be installed below, as shown in Figure 7. Two pull-rope displacement sensors 4 can be installed under the first slidable base 3 , as shown in FIG. 6 .

The two slidable bases in the present invention are the first type of slidable bases, and two pull-string displacement sensors 4 are installed on the two slidable bases, and the other slidable base of the present invention is the second type of slidable base The base, the three pull-string displacement sensors 4 are mounted on this slidable base. The cable displacement sensor 4 is fixed on the slidable base 3 by the socket head cap screws 18 .

The pull-rope displacement sensor 4 is connected to the target 5 through the pull-rope 6, and the target 5 is connected to the measured mechanism; in this preferred embodiment, the target 5 is designed as a plate in the shape of an equilateral triangle, and there are three designated positions 19 on the plate, Connect the three pull ropes 6 of one of the slidable bases to three designated positions 19 respectively, and connect the four pull ropes 6 of the other two slidable bases to the three designated positions according to the ratio of 2:1:1 19 , this structure is used for parameter calculation.

During the movement of the measured mechanism, the target 5 is driven to move, thereby driving the rope length of the rope displacement sensor 4 to change. The present invention can move with the tested mechanism, and is not limited by factors such as the surrounding environment, the speed of the tested object, and the angle change, and is widely used in most testing mechanisms, with strong practicability;

An information processing panel 13 is placed directly under the main support 1, and the information processing panel 13 is connected to the pull rope displacement sensor 4 and fed back to the information processing panel 13. The information processing panel 13 collects the change data of the rope length for use in the calculation of other performance parameters . The information processing panel 13 mainly includes the function of parameter calculation based on the change data of the rope length.

A spirit level 20 is placed in a central position just above the main support 1 . By observing the spirit level 20 , the position of the testing device can be regulated during the installation process, so that the testing device is in a horizontal position.

A portable rigid-flexible composite mechanism and robot performance test method, as shown in Figure 10 is a schematic diagram of the test method, the test method includes:

1) The structure of the test device is simplified: the position of the slidable base 3 is set as three points ABC to form a triangle ABC, there are three designated positions 19 on the target 5, and the three designated positions 19 are set as the three points of DEF, forming a triangle DEF, the overall shape Similar to the two upper and lower triangles, then connect the three pull ropes 6 of one of the slidable bases 3 to the three designated positions 19 respectively, and the four pull ropes 6 of the other two slidable bases 3 according to 2:1:1 The proportions are respectively connected at three designated positions 19, and the pull rope is set as a line segment, and the three points ABC and DEF are connected by the line segment, that is, the length of the seven line segments AE, AD, AF, BE, BF, CF, CD;

2) Re-simplification: The structure can be further divided into three triangular pyramids, namely triangular pyramid F-ABC, triangular pyramid E-FAB, triangular pyramid D-FAC, with point A as the coordinate origin, and the Z axis is perpendicular to the plane where the triangle ABC is located. Up, the straight line where AC is located is the direction of the Y-axis, and the direction of the X-axis is the vector cross product of the Z-axis and the Y-axis;

3) Parameter calculation: In the triangular pyramid F-ABC, the coordinates of the three points of the triangle ABC are known, and the lengths of the three edges are respectively l _FA , l _FB , l _FC , and the following equation can be established from the geometric relationship:

From this, the coordinates of point F can be obtained, that is, the three values of x _F , y _F , and z _F ; in the same way, the coordinates of two points D and E can be obtained, and then the coordinates of the middle point of the triangle DEF can be obtained, that is, the The movement position of the measuring mechanism;

Repeat the calculation of the collected rope length change data according to the above steps, and you can get all the point sets of the coordinates of the middle point of the triangle DEF, that is, the motion trajectory of the tested mechanism;

Based on the motion trajectory, and then converted with time, the motion speed of the tested mechanism can be obtained.

In the present invention, the motion acceleration of the measured mechanism can be obtained by converting with time based on the motion speed.

The side lengths of the triangle DEF and the triangle ABC can be determined according to the position of the designated position 19 and the position of the slidable base 3 in actual work, respectively, which provides more flexibility for the present invention.

The above are only specific embodiments of the present invention, and do not limit the protection scope of the present invention. All equivalent changes made according to the design ideas of this case fall into the scope of protection of this case.

Claims (3)

1. A method for testing performance of a portable rigid-flexible composite mechanism and a robot is characterized in that: the test method relates to a portable rigid-flexible combined mechanism and robot performance test device, which comprises a main support, three telescopic arms, a slidable base, a stay cord displacement sensor, a target, a stay cord and an information processing panel, wherein the main support is respectively connected with the three telescopic arms through a double-headed ball connecting rod, the three telescopic arms are respectively provided with a slidable base, the slidable bases are slidably fixed on the telescopic arms, two stay cord displacement sensors are respectively arranged on two slidable bases, the other slidable base is provided with three stay cord displacement sensors, the stay cord displacement sensors are connected with the target through the stay cord, the target is connected on a mechanism to be tested, the connecting ends of the main support are provided with nine positioning pins, each connecting end is inserted with three positioning pins, one positioning pin is arranged right above the connecting end, the other two positioning pins are respectively arranged at two sides of the connecting end, correspondingly, three positioning pins are inserted into each telescopic arm, buckles are connected between the corresponding positioning pins, a main support and the telescopic arms are firmly and horizontally combined together during connection, the connecting end of the main support is designed into an inward inclined slope shape, when the buckles right above the main support are loosened, the telescopic arms can rotate downwards to be in a vertical state from the horizontal direction around the inclined connecting end of the main support under the assistance of the double-head ball connecting rod, the positioning pins at two sides and the buckles, and if the telescopic arms are not used, the slidable base, the stay cord displacement sensor and the target can be independently disassembled; the information processing panel is placed to the main support, and the stay cord displacement sensor is connected to the information processing panel, and the information processing panel is collected the change data of rope length, and based on the change data of rope length, this test method includes: 1) the structure of the testing device is simplified: with slidable baseThe position is ABC three point, constitutes triangle-shaped ABC, has three assigned position on the target, sets up three assigned position and is DEF three point, constitutes triangle-shaped DEF, then will connect three assigned position respectively with three stay cords of one of them slidable base, four stay cords on two other slidable bases are according to 2: the ratio of 1:1 is respectively connected with three designated positions, the pull rope is set as a line segment, and three points ABC and three points DEF are connected through the line segment, namely the lengths of seven line segments AE, AD, AF, BE, BF, CF and CD; 2) and then simplifying: the structure can be subdivided into three triangular pyramids, namely a triangular pyramid F-ABC, a triangular pyramid E-FAB and a triangular pyramid D-FAC, wherein the point A is taken as the origin of coordinates, the Z axis is vertical to the plane of the triangle ABC and faces upwards, the straight line where the AC is located is the direction of the Y axis, and the direction of the X axis is the vector cross product of the Z axis and the Y axis; 3) and (3) parameter calculation: in the triangular pyramid F-ABC, the coordinates of three points of the triangle ABC are known, and the lengths of three edges are respectively l_FA、l_FB、l_FCFrom the geometric relationship, the following equation can be established:

the coordinates of the F point, i.e. x, can thus be obtained_F、y_F、z_FThree values; similarly, coordinates of two points D, E can be obtained, and then coordinates of a middle point of the triangle DEF, namely the motion position of the mechanism to be measured, can be obtained; calculating the collected rope length change data repeatedly according to the steps to obtain all point sets of the coordinates of the DEF intermediate point of the triangle, namely the motion trail of the mechanism to be measured; and converting with time based on the motion trail to obtain the motion speed of the mechanism to be measured.

2. The method for testing the performance of a portable rigid-flexible combined mechanism and robot as claimed in claim 1, wherein: the side lengths of the triangles DEF and ABC can be determined according to the specified position in actual operation and the position of the slidable base, respectively.

3. The method for testing the performance of a portable rigid-flexible combined mechanism and robot as claimed in claim 1, wherein: and converting the movement speed and the time to obtain the movement acceleration of the mechanism to be measured.

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