CN203831398U - 6-PTRT type parallel-connected robot with automatic calibrating function - Google Patents

Abstract

The utility model provides a 6-PTRT type parallel robot with a self-calibration function, which includes a static platform, a dynamic platform, six sets of linkage mechanisms connected between the static platform and the dynamic platform, and a drive connected to the linkage mechanism. The parallel robot composed of the device also includes a calibration device. The calibration device includes a truss structure with regular hexagons up and down, six wire sensors and six wire ropes. The parallel robot is fixedly installed on the bottom of the truss structure. The stay wire sensors are respectively fixed on the six corners of the regular hexagon above the truss structure, one end of each stay wire rope is fixed on a stay wire sensor, and the other end is fixed on the moving platform. The utility model not only has six degrees of freedom to realize complete spatial positioning and posture simulation, but also can calibrate the six-degrees-of-freedom platform. The utility model has the advantages of compact structure, small volume, light weight, low manufacturing cost, and easy computer programming control.

Description

A 6-PTRT type parallel robot with self-calibration function

technical field

The utility model relates to a parallel robot, specifically a parallel robot with a self-calibration function.

Background technique

Parallel robots have the advantages of high precision, high stiffness, small inertia, high load capacity, simple motion inverse model, high operating speed, and easy control. It has become one of the important branches of robot research and is widely used in various fields. The parallel mechanism has 2, 3, 4, 5 or 6 degrees of freedom, among which the 6 degrees of freedom parallel robot can complete the position and attitude positioning at the same time, which can be used to simulate the pose of the object, so it is favored by more scholars. Although the research on the 6-DOF parallel mechanism is relatively comprehensive, there are still deficiencies. The previous 6-DOF parallel mechanism is formed by connecting the upper and lower platforms with 6 rods. The upper and lower platforms are connected by spherical hinges and Hooke hinges respectively, so that the upper platform and the lower platform can perform 6 independent movements, and can move in any direction and rotate around the axis of any direction and position in three-dimensional space. But there are few parallel mechanisms with self-calibration function. And these six struts are mostly electric cylinders, which are bulky, and the mechanism is relatively complicated and difficult to process and the cost is too high. This design is driven by a linear stepping motor. The connecting rod mechanism is relatively simple and flexible, has a compact structure, greatly improves the running accuracy, and is easy to be controlled by a computer.

Contents of the invention

The purpose of the utility model is to provide a 6-PTRT type parallel robot mechanism with a self-calibration function that is ingenious in mechanism, stable and flexible, relatively low in cost and easy to be controlled by a computer.

The utility model is realized in this way: it includes a parallel robot composed of a static platform, a dynamic platform, six sets of linkage mechanisms connected between the static platform and the dynamic platform, and a drive device connected to the linkage mechanism, and also includes a calibration device. The calibration device includes a regular hexagonal truss structure up and down, six stay wire sensors and six stay wire ropes, the parallel robot is fixedly installed at the bottom of the truss structure, and the six stay wire sensors are respectively fixed on the regular hexagon above the truss structure. On the six corners of each stay wire rope, one end of each stay wire rope is fixed on a stay wire sensor, and the other end is fixed on the moving platform.

The utility model also includes such structural features:

1. The drive device includes a motor mounting bracket, six linear stepping motors, and six limit switches. The six linear stepping motors are respectively installed on the motor mounting bracket, and the upper end of the motor output shaft is connected with the linkage mechanism. The lower end of the output shaft is in one-to-one correspondence with the limit switches installed on the base plate.

2. A kind of 6-PTRT type parallel robot with self-calibration function according to claim 1 or 2, it is characterized in that: described link mechanism comprises universal joint A, universal joint B, universal joint connection Device, connecting column A, connecting column B, one end of connecting column A is connected to one end of universal joint A, the other end of connecting column A is connected to the moving platform, and the other end of universal joint A is connected to the universal joint through the universal joint connecting device. One end of the joint B is connected, one end of the connecting column B is connected with the other end of the universal joint B, the other end of the connecting column B is connected with the slider installed on the static platform, and the upper end of the output shaft of the motor is connected with the connecting rod mechanism Connected means that the upper end of the motor output shaft is connected with the slide block.

3. The universal joint connecting device includes a large shaft, a small shaft and a deep groove ball bearing, one end of the large shaft is connected to the universal joint B, and the other end of the large shaft is connected to one end of the small shaft through a deep groove ball bearing, The other end of the small shaft is connected with universal joint A.

A 6-PTRT type parallel robot mechanism provided by the utility model has the following characteristics: 1. The realization mechanism of the utility model with six degrees of freedom is simple and easy to process and control. 2. The self-calibration detection device of the utility model can detect the actual running state of the platform, calculate the error of some parameters through the error mathematical model, the actual pose and the input of the motor, complete the self-calibration of the robot, and greatly improve the running accuracy. 3. The utility model has the advantages of compact structure, flexible movement, and large working space, which can better meet people's requirements for using a 6-degree-of-freedom parallel mechanism. 4. The utility model can be widely used in spatial positioning and pose simulation of objects. 5. The six degrees of freedom of the utility model are driven by six linear stepping motors and have limit switches, so the movement safety is high. 6. The connecting rod mechanism of the utility model avoids the use of ball joints and electric cylinders, which reduces the cost and the complexity of the mechanism. The motor is installed on the fixed platform, which greatly reduces the quality of the moving structure, and the handling is more sensitive and the response speed is fast.

Description of drawings

Fig. 1 is the overall structure figure of the utility model;

Fig. 2 is a schematic diagram of the mechanism of the six-degree-of-freedom motion platform of the present invention;

Fig. 3 is a schematic diagram of the mechanism of the driving device of the present invention;

Fig. 4 is the structural representation of the calibration device of the present utility model;

Fig. 5 is the structural representation of link mechanism;

Fig. 6 is a schematic structural view of the universal joint connection device.

Detailed ways

Provide the specific embodiment of the present utility model below, and illustrate in conjunction with accompanying drawing.

In conjunction with Fig. 1, a 6-PTRT type parallel robot mechanism of the utility model is mainly composed of a six-degree-of-freedom motion platform 1, a driving device 2, and a detection device 3. The six-degree-of-freedom motion platform 1 can control objects in space Complete positioning can also simulate the spatial attitude of the object; the driving device 2 is composed of six linear stepper motors and zero position detection, and is mainly used to drive the movement of the six-degree-of-freedom platform; the calibration device 3 detects six regular hexagonal trusses The cable sensors on the corners obtain the actual position and attitude of the moving platform through kinematics.

Combined with Figure 2, the six-degree-of-freedom motion platform 1 mainly includes a moving platform 1-1, a linkage mechanism 1-2, a guide rail mounting frame 1-3, a guide rail 1-4, a slider 1-5, a static platform 1-6, a pad Blocks 1-7. 6 pads 1-7 are fixed with screws on the static platform 1-6, a guide rail mounting bracket 1-3 is vertically fixed on each pad 1-7, and 6 linear guide rails 1-4 are installed on the On the linear guide rail bracket 1-3, the slider 1-5 and the guide rail 1-4 are used together to form a moving pair P that is perpendicular to the radial direction of the fixed platform 1-6 and moves linearly. The lower end of each link mechanism 1-2 passes through the The screws are installed on the slide block 1-5, and the upper ends are connected with the moving platform 1-1, and each link mechanism has two universal joints and a rotating pair, thereby forming a 6-PTRT type parallel robot.

Combining Figure 2 and Figure 3, the driving device 2 mainly includes the upper end of the motor output shaft 2-1, the motor mounting bracket 2-2, the linear stepper motor 2-3, the lower end of the motor output shaft 2-4, the column A2-5, the leveling Screw 2-6, limit switch 2-7, limit switch mounting bracket 2-8, bottom plate 2-9, column B2-10. Threaded holes are reserved at the four corners of the bottom plate 2-9, and the bottom plate 2-9 and the motor mounting bracket 2-2 are connected through four columns B2-10, and the motor mounting bracket 2-2 is connected through four columns A2-5. 2 is connected with static platform 1-6. 6 linear stepping motors 2-3 are fixed on the motor mounting bracket 2-2 by screws, the upper end of the motor output shaft 2-1 is connected to the connecting rod mechanism 1-2, and 6 limit positions are fixed on the bottom plate 2-9 The switch 2-7 corresponds to the lower end of the motor output shaft 2-4. When the lower end of the motor output shaft 2-4 touches the lower switch 2-7, a signal will be generated to determine the zero position of the device and protect the device. Four leveling screws 2-6 are installed on the bottom of the base plate 2-9, and the levelness of the equipment can be adjusted by the leveling screws 2-6.

Combining Figure 2 and Figure 4, the calibration device 3 mainly includes a cable sensor mounting bracket 3-1, a column 3-2, a cable sensor 3-3, a cable cable 3-4, an aluminum tube 3-5, and an L-shaped connection block 3-6 , beam 3-7. Columns 3-2, aluminum tubes 3-5 and beams 3-7 are all processed from square aluminum tube profiles and combined into a truss structure with regular hexagons up and down. The beams 3-7 and aluminum tubes 3-5 pass through the L Type connection block connection, and the rest are connected together by welding. The upper parts of the six uprights 3-2 are respectively equipped with a stay wire sensor 3-3 through a stay wire sensor mounting bracket 3-1. One end of the six stay wires 3-4 is fixed on the stay wire sensor, and the other end is fixed on the moving platform 1-1. When the moving platform 1-1 moves, the length of the stay wire 3-4 will change. The change amount of the pull wire 3-4 can be detected by the pull wire sensor, and the actual position and state of the platform can be calculated through kinematics. Through the error mathematical model and the actual pose and the input of the motor, the error of some parameters is solved, and the self-calibration of the robot is completed.

Combining Figure 2, Figure 3 and Figure 5, the linkage mechanism 1-2 mainly includes connecting column A1-2-1, set screw 1-2-2, universal joint A joint 1-2-3, universal joint A Joint 1-2-4, universal joint connection device 1-2-5, universal joint B joint 1-2-6, connecting column B1-2-7, universal joint B joint 1-2-8. The slider 1-5 is installed on the connecting column B1-2-7 through four screws, and the connecting column B1-2-7 is connected with the universal joint B joint b through the set screw, and the universal joint connecting device 1-2- 5 One end is connected to the universal joint B joint a1-2-6, the other end is connected to the universal joint A joint b1-2-4, and the universal joint A joint a is connected to the connecting column A1- 2-1 are connected, thus forming the link mechanism 1-2 of the six-degree-of-freedom platform. The connecting column A1-2-1 is connected to the moving platform 1-1, and the connecting column B1-2-7 is connected to the upper end of the motor output shaft 2-1, so that when the linear stepping motor 2-3 moves, it can drive the moving platform. Platform 1-1 movement up.

5 and 6, the universal joint connection device 1-2-5 mainly includes a small shaft 1-2-5-1, a bearing end cover 1-2-5-2, a deep groove ball bearing 1-2-5- 3. Large axis 1-2-5-4. One end of the small shaft 1-2-5-1 is connected with the universal joint A joint b1-2-4 through a set screw, and the other end is equipped with a deep groove ball bearing 1-2-5-3 inserted into the large shaft 1-2- In the groove of 5-4, the bearing end cover 1-2-5-2 is installed at the groove mouth to fix the bearing, so that the small shaft 1-2-5-1 can rotate around the axis of the large shaft to form a rotation Vice, large shaft 1-2-5-4 is also connected with universal joint B joint a through set screws, so that the two universal joints are connected together and the guide rail slider forms a connecting rod, 6 Such upper and lower links are connected in parallel to form a 6-PTRT type parallel robot.

The function of a 6-PTRT type parallel robot with calibration function of the utility model is generally described in conjunction with Figures 1-6. The utility model is mainly composed of a six-degree-of-freedom motion platform 1, a driving device 2 and a calibration device 3. The six-degree-of-freedom motion platform 1 can be widely used for spatial positioning and pose simulation of objects. The dynamic platform 1-1 and the static platform 1-6 are connected in parallel through six branches (connecting rods 1-2) with the same structure. Connected, the connecting rod 1-2 is composed of two universal joints and a universal joint connecting device 1-2-5, which can form a rotating joint between the two universal joints, plus two guide rails 1-4 and slider 1-5 constitute the moving pair, which constitutes a PTRT-type connecting rod member. When such six connecting rods move, they can drive the moving platform 1-1 to move, and the driving device 2 uses 6 The linear stepper motor 2-3 drives the six connecting rods 1-2 to move, and the upper end 2-1 of the motor output shaft is connected to the guide rail slider mechanism, so that the motor can drive the connecting rod 1-2 to move, and the motor output Six limit switches 2-7 are arranged below the lower end 2-4 of the shaft. The limit switches are helpful for the initialization of the mechanism and improve the movement accuracy and safety of the mechanism. The leveling screws at the bottom of the bottom plate 2-9 can make the whole device In the horizontal state, the linear stepper motor 2-3 is installed on the static platform to reduce the quality of the moving components, so that the handling is more sensitive and the rigidity is good. The detection device 3 can detect the length changes of several pull wires, and then obtain the actual pose of the six-degree-of-freedom platform, and obtain the error values of some parameters through the error model function to complete the self-calibration of the robot.

Claims (4)

1. A 6-PTRT type parallel robot with self-calibration function, including a parallel robot consisting of a static platform, a dynamic platform, six sets of linkage mechanisms connected between the static platform and the dynamic platform, and a drive device connected to the linkage mechanism. The robot is characterized in that: it also includes a calibration device, the calibration device includes a regular hexagonal truss structure up and down, six stay wire sensors and six stay wire ropes, the parallel robot is fixedly installed on the bottom of the truss structure, six The stay wire sensors are respectively fixed on the six corners of the regular hexagon above the truss structure, one end of each stay wire rope is fixed on a stay wire sensor, and the other end is fixed on the moving platform. the 2. A kind of 6-PTRT type parallel robot with self-calibration function according to claim 1, is characterized in that: described driving device comprises motor mounting bracket, six linear stepping motors, six limit switches, The six linear stepping motors are installed on the motor mounting bracket respectively, the upper end of the motor output shaft is connected with the linkage mechanism, and the lower end of the motor output shaft corresponds to the limit switch installed on the base plate. the 3. A kind of 6-PTRT type parallel robot with self-calibration function according to claim 2, is characterized in that: described link mechanism comprises universal joint A, universal joint B, universal joint connecting device, Connecting column A, connecting column B, one end of connecting column A is connected with one end of universal joint A, the other end of connecting column A is connected with moving platform, and the other end of universal joint A is connected with universal joint through universal joint connecting device One end of B is connected, one end of connecting column B is connected with the other end of universal joint B, the other end of connecting column B is connected with the slider installed on the static platform, and the upper end of the motor output shaft is connected with the linkage mechanism Refers to the connection between the upper end of the output shaft of the motor and the slider. the 4. A kind of 6-PTRT type parallel robot with self-calibration function according to claim 3, it is characterized in that: described universal joint connecting device comprises large shaft, small shaft and deep groove ball bearing, the large shaft One end is connected with the universal joint B, the other end of the large shaft is connected with one end of the small shaft through a deep groove ball bearing, and the other end of the small shaft is connected with the universal joint A. the