CN105171723A - Integrated two-degree-of-freedom manipulator and control system thereof - Google Patents

Abstract

The invention discloses an integrated two-degree-of-freedom manipulator and a control system thereof. The two-degree-of-freedom manipulator comprises a screw and a spline which are horizontally arranged in the Z-axis direction and fixedly connected by a spline and screw connection piece; a servo motor which is arranged below the screw; a hollow motor which is arranged below the spline; an encoder which is arranged on the hollow motor and through which the spline passes; a fixation plate which comprises a bottom plate and a back side plate which are mutually perpendicularly arranged, wherein the servo motor and the hollow motor are fixedly mounted on the bottom plate, and the spline and screw connection piece is slideably mounted on the back side plate. The linear displacement and rotation movement of the mechanism can be achieved by the hollow motor and the servo motor, namely the linear displacement and the rotation movement in the plane in the vertical displacement direction can be achieved, the transmission precision is high, the volume is small, the structure is simple, and the manufacture cost is low.

Description

Integrated two-degree-of-freedom manipulator and its control system

technical field

The invention relates to the technical field of industrial robots, in particular to an integrated two-degree-of-freedom manipulator and its control system.

Background technique

With the continuous development of my country's economy and the rapid advancement of science and technology, and the goal of Made in China 2025, industrial robots will be more widely used in various fields of manufacturing.

The integrated two-degree-of-freedom manipulator is an important part of industrial robots. As a direct execution part, it is widely used in the field of automatic plug-in, soldering, dispensing, patching and other mounting technologies. Its own structure, weight, dimensions and precision have a direct impact on the working performance and technical performance of the entire robot. At present, the existing linear and rotary motion mechanisms generally use adapters such as synchronous belts and chains to realize the motion transmission between the driving part and the driven part, and the movement between the driving part and the driving part, and between the driving part and the driven part The distribution is not on the same axis, so the existing linear and rotary motion mechanism has the problems of low efficiency, poor precision, complex structure, and high manufacturing cost.

Therefore, in view of the above technical problems, it is necessary to provide an integrated two-degree-of-freedom manipulator and its control system.

Contents of the invention

In view of this, the object of the present invention is to provide an integrated two-degree-of-freedom manipulator and its control system, which is a linear plus rotary motion mechanism, which can optimize the structure, improve performance, increase efficiency and precision, and reduce manufacturing costs. cost.

In order to achieve the above object, the technical solutions provided by the embodiments of the present invention are as follows:

An integrated two-degree-of-freedom manipulator, the two-degree-of-freedom manipulator includes:

a screw rod and a spline located in the direction of the Z axis, the screw rod and the spline are arranged horizontally, and the screw rod and the spline are fixedly connected by a spline screw connector;

Servo motor located under the screw;

A hollow motor around the spline;

an encoder on the hollow motor, the splines passing through the encoder;

The fixed plate includes a base plate and a rear side plate arranged perpendicularly to each other, the servo motor and the hollow motor are fixedly installed on the base plate, and the spline screw connecting piece is slidably installed on the rear side plate;

When the servo motor rotates, the screw drives the spline to move in the direction of the Z axis through the splined screw connector, and when the hollow motor rotates, the spline rotates in a plane perpendicular to the Z axis.

As a further improvement of the present invention, a shaft coupling is fixed between the servo motor and the lead screw.

As a further improvement of the present invention, the coupling is fixedly installed on the rotating shaft of the servo motor, the other end of the coupling is fixedly installed with the screw rod, and the outer cylinder of the coupling and the coupling cover are installed on the outside of the coupling plate, and a bearing for fixed installation with the screw rod is also installed on the outer cylinder of the coupling.

As a further improvement of the present invention, upper and lower hard stops corresponding to the screw rods are provided on the rear side plate.

As a further improvement of the present invention, a slide rail along the Z-axis direction is fixedly installed on the rear side plate, and a slide block is fixedly installed on the spline screw connector, and the slide block is fixed on the slide rail along the Z-axis direction. direction up and down.

As a further improvement of the present invention, the hollow motor includes a hollow motor stator, a hollow motor rotor located outside the hollow motor stator, and a permanent magnet patch located outside the hollow motor rotor.

As a further improvement of the present invention, the upper limit photoelectric switch and the lower limit photoelectric switch corresponding to the spline are fixedly installed on the rear side plate, and the upper limit photoelectric switch and the lower limit photoelectric switch are fixedly installed on the spline screw connector. The corresponding photoelectric switch stopper of the switch.

As a further improvement of the present invention, several reinforcing ribs are fixedly installed at the connection between the bottom plate and the rear side plate.

Correspondingly, an integrated two-degree-of-freedom manipulator control system, the control system includes: a computer, a controller connected to the computer, and a first driver and a second driver connected to the controller, the first driver It is used to drive the servo motor, and the second driver is used to drive the hollow motor and receive the position feedback information of the encoder to ensure the motion accuracy of the hollow motor.

As a further improvement of the present invention, the controller uses pulses to drive the servo, the number of pulses determines the number of rotations of the servo motor and/or the hollow motor, and the pulse frequency determines the rotation speed of the servo motor and/or the hollow motor.

The beneficial effects of the present invention are:

The invention utilizes a hollow motor and a servo motor to realize the linear displacement and rotational motion of the mechanism, that is, the linear displacement and the rotational motion in the plane of the vertical displacement direction can be realized, and the transmission precision is high, the volume is small, the structure is simple, and the manufacturing cost is low.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic cross-sectional structural view of an integrated two-degree-of-freedom manipulator in a specific embodiment of the present invention;

2 is a schematic diagram of the three-dimensional structure of the integrated two-degree-of-freedom manipulator in a specific embodiment of the present invention;

Fig. 3 is a schematic diagram of a control system module of an integrated two-degree-of-freedom manipulator in a specific embodiment of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

The invention discloses an integrated two-degree-of-freedom manipulator, and the two-degree-of-freedom manipulator includes:

A screw and a spline located in the direction of the Z axis, the screw and the spline are arranged in parallel, and the screw and the spline are fixedly connected by a splined screw connector;

Servo motor located under the screw;

A hollow motor around the spline;

an encoder on the hollow motor, the splines passing through the encoder;

The fixed plate includes a base plate and a rear side plate arranged perpendicularly to each other, the servo motor and the hollow motor are fixedly installed on the base plate, and the spline screw connecting piece is slidably installed on the rear side plate;

When the servo motor rotates, the screw drives the spline to move in the direction of the Z axis through the splined screw connector, and when the hollow motor rotates, the spline rotates in a plane perpendicular to the Z axis.

The invention also discloses an integrated two-degree-of-freedom manipulator control system, the control system includes: a computer, a controller connected to the computer, and a first driver and a second driver connected to the controller, the first One driver is used to drive the servo motor, and the second driver is used to drive the hollow motor and receive position feedback information from the encoder to ensure the motion accuracy of the hollow motor.

Referring to Fig. 1 and Fig. 2, it is a schematic structural diagram of an integrated two-degree-of-freedom manipulator in a specific embodiment of the present invention.

In this embodiment, the upper end surface of the middle part of the outer cylinder 11 is closely matched and fixed with the end surface of the lower hole of the bottom plate 25, the upper end surface of the outer cylinder 11 is matched and fixed with the lower end surface of the conversion part 10, and the lower end surface of the spline motor spline connector 9 is matched with the lower end surface of the spline motor. The upper end surface of the transition piece 10 is fitted and fixed.

Assemble the assembled hollow motor with the base plate. The hollow motor in this embodiment includes a hollow motor stator 15, a hollow motor rotor 13 positioned outside the hollow motor stator, and a permanent magnet patch 14 positioned outside the hollow motor rotor. The sheet 14 and the hollow motor rotor 13 are installed with the outer cylinder 11 through the bearing 12 . The hollow motor rotor 13 of the hollow motor cooperates with the hole in the middle of the spline motor spline connector 9 to ensure that the ring at the lower part of the hollow motor is inserted into the hole at the upper end of the base plate 25, and also to ensure that the finishing surface of the lower end of the hollow motor is in contact with the base plate The protruding fine car surface of 25 tops fits closely, and finally fixes the hollow motor.

Support block 23 is packed on the back side plate 29 with screw, and lower limit photoelectric switch 16, upper limit photoelectric switch 18 are assembled on the back side plate 29 with screw. The lower hard limiter 2 is installed on the shaft coupling outer cylinder 5 upper ends. The cross end of the bottom plate where the coupling outer cylinder 5 is located is in interference fit with the cross groove of the rear side plate 29 .

The lower end of the screw rod 1 is in interference fit with the inner ring of the corresponding bearing 3, and the inner ring of the bearing is pressed by the compression nut 4 of the inner ring of the bearing. Pass the partially assembled screw through the lower end of the coupling outer cylinder 5, install the bearing 3 into the hole at the upper end of the coupling outer cylinder 5, and cover the coupling bearing cover plate 6 to the end face of the outer ring of the bearing 3 fixed. Coupling 7 one ends are assembled on the rotating shaft of servomotor, and fix with set screw.

Put the servo motor into the hole on the lower side of the bottom plate where the coupling outer cylinder 5 is located, so that the other end of the coupling 7 is mounted on one end of the screw rod, and the front end of the servo motor is closely matched and fixed with the upper surface of the hole, and then Fix on one end of the screw mandrel with set screw coupling 7.

Finally, assemble the partially assembled rear side panel 29 and the bottom panel 25 to ensure that they are perpendicular. The slide rail 31 is assembled to the strip-shaped finishing position of the rear side plate 29 to ensure the sag of the slide rail 31 . The encoder 22 is sleeved on the rotating shaft of the hollow motor and fixed. The upper end of the spline 19 is interference-fitted with the inner ring of the corresponding bearing 17, and the inner ring of the bearing is pressed with the compression nut 33 of the inner ring of the bearing. Insert the partially assembled spline into the hole of the spline slider 34, insert the outer ring of the bearing into the hole of the screw slider, and press the outer ring end face of the bearing 17 with the spline bearing outer ring cover 21 . The spline slide block 34 on the rear side of the spline screw rod connector 28 slides into the corresponding groove of the spline screw rod connector 28 . The spline 19 is inserted into the hollow shaft of the hollow motor, and the screw flange nut 27 is inserted into the corresponding hole of the spline screw connector 28, and fixed with screws. The spline screw connecting piece 28 and the slide block 32 are fixed with screws. Adjust the position of the spline slider 34 to ensure the concentricity of the spline 19, the hollow motor rotor 13, and the outer tube 11, and then fix the spline slider 34 with set screws. Upper hard limiter 30 is screwed on rear side plate 29.

Finally, when the photoelectric switch is energized, the upper limit photoelectric switch 16 and the lower limit photoelectric switch 18 are adjusted, and the photoelectric switch block 20 is fixed to the splined screw connector 28 with screws.

The bottom end of the spline can use the flange to connect the manipulator to complete the gripping of objects and plug-ins. The connection nozzle can be used for patching, wafer cutting, and connected to the welding machine to complete soldering.

When the servo motor 26 rotates, it drives the shaft coupling 7 to rotate, thereby causing the screw mandrel 1 to rotate, and then drives the lifting of the screw flange nut 27, and also drives the lifting of the spline screw connecting piece 28, thereby realizing the spline screw connection. 19 Up and down movement parallel to the Z axis. The rotation of the hollow motor rotor 13 drives the rotation of the splines 19, thereby realizing the rotational movement in a plane perpendicular to the Z axis.

In this embodiment, reinforcing ribs 8 and 24 are fixedly installed at the joints of the bottom plate 25 and the rear side plate 29, and the reinforcing ribs are triangular, and in other embodiments, the reinforcing ribs may also be of other shapes.

Further, in the present invention, the thread lead angle λ of the screw rod is less than the equivalent friction angle Φ _v , so as to prevent self-locking and ensure good transmission performance.

Compared with the existing products, the linear plus rotary motion mechanism in the present invention optimizes the structure, improves the performance, improves the efficiency and precision, and reduces the manufacturing cost at the same time, so the present invention has important practical significance. The present invention utilizes a servo motor and a hollow motor to drive the screw and the spline respectively, and the counter bearing on the screw nut pair and the spline is directly connected by a metal block. Such a structure reduces the cumulative error and improves the response of the mechanism speed and transmission accuracy. Moreover, the hollow motor and the spline, the servo motor and the screw are separated on two different parallel axes on the same plane, which realizes the decoupling of linear motion and rotary motion. The invention has the advantages of simple structure, greatly reduced mechanism volume and reduced processing cost.

Referring to Fig. 3, it is a control system of an integrated two-degree-of-freedom manipulator in an embodiment of the present invention, which includes: a computer 35, a controller 36 connected to the computer, and a first driver 37 and a second driver connected to the controller. The driver 38, the first driver 37 is used to drive the servo motor, and the second driver 38 is used to drive the hollow motor and receive encoder position feedback information to ensure the motion accuracy of the hollow motor.

The computer 35 can program the controller 36 according to the movement requirements, and the controller 36 can send pulses to the first driver 37 and the second driver 38 to achieve the purpose of controlling the movement of the motor. The built-in encoder of the servo motor feeds back the real-time position of the servo motor to the first driver to ensure the position accuracy of the servo motor; the encoder can feed back the real-time position of the hollow motor to the second driver to ensure the accuracy of the hollow motor. Motion accuracy; the computer can monitor the motion state of the two-degree-of-freedom manipulator throughout the process.

Specifically, the computer 35 and the controller 36 are connected through an Ethernet line, and can exchange information. The controller 36 is connected with the first driver 37 and the second driver 38, the upper limit photoelectric switch and the lower limit photoelectric switch by a control bus, wherein it can exchange information with the first driver and the second driver, and can only receive Photoelectric switch information.

The first driver 36 and the servo motor form a closed-loop control loop, and the subsystem formed by the second driver 38 , the hollow motor and the encoder forms a closed-loop control loop.

The control system software in the computer 35 can program the controller 36. The controller 36 drives the servo in the form of pulses. The number of pulses determines the number of turns of the motor, and the pulse frequency determines the speed of rotation of the motor. The driver 38 can feed back the positions of the servo motor and the hollow motor to the controller 36 in real time, and at the same time, the controller 36 can also transmit the data to the control system software in the computer. In particular, it should be pointed out that the encoder in the present invention is the position feedback of the hollow motor, and the upper and lower photoelectric switches feed back the position signal of the screw spline connector to the controller 36 .

The invention can be applied to various automation equipment, and is suitable for linear displacement motion and rotation. The fixed plate has mounting threaded holes, combined with X, Y moving platforms, can realize four-degree-of-freedom motion.

As can be seen from the above technical solutions, the present invention has the following beneficial effects:

The invention utilizes a hollow motor and a servo motor to realize the linear displacement and rotational motion of the mechanism, that is, the linear displacement and the rotational motion in the plane of the vertical displacement direction can be realized, and the transmission precision is high, the volume is small, the structure is simple, and the manufacturing cost is low.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only includes an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (10)

1. An integrated two-degree-of-freedom manipulator, characterized in that the two-degree-of-freedom manipulator comprises: A screw and a spline located in the direction of the Z axis, the screw and the spline are arranged in parallel, and the screw and the spline are fixedly connected by a splined screw connector; Servo motor located under the screw; A hollow motor around the spline; an encoder on the hollow motor, the splines passing through the encoder; The fixed plate includes a base plate and a rear side plate arranged perpendicularly to each other, the servo motor and the hollow motor are fixedly installed on the base plate, and the spline screw connecting piece is slidably installed on the rear side plate; When the servo motor rotates, the screw drives the spline to move in the direction of the Z axis through the splined screw connector, and when the hollow motor rotates, the spline rotates in a plane perpendicular to the Z axis. 2. The integrated two-degree-of-freedom manipulator according to claim 1, wherein a shaft coupling is fixed between the servo motor and the screw rod. 3. The integrated two-degree-of-freedom manipulator according to claim 2, wherein the shaft coupling is fixedly mounted on the rotating shaft of the servo motor, the other end of the shaft coupling is fixedly mounted on the screw rod, and the shaft coupling A coupling outer cylinder and a coupling cover are installed on the outer side of the coupling, and a bearing for fixed installation with the screw rod is also installed on the coupling outer cylinder. 4 . The integrated two-degree-of-freedom manipulator according to claim 1 , wherein an upper hard stop and a lower hard stop corresponding to the screw rod are provided on the rear side plate. 5. The integrated two-degree-of-freedom manipulator according to claim 1, wherein a slide rail along the Z-axis direction is fixedly installed on the rear side plate, and a The slider moves up and down along the Z-axis on the slide rail. 6. The integrated two-degree-of-freedom manipulator according to claim 1, wherein the hollow motor comprises a hollow motor stator, a hollow motor rotor positioned outside the hollow motor stator, and a permanent magnet sticker positioned outside the hollow motor rotor piece. 7. The integrated two-degree-of-freedom manipulator according to claim 1, wherein an upper limit photoelectric switch and a lower limit photoelectric switch corresponding to the spline are fixedly installed on the rear side plate, and the spline screw rod is connected A photoelectric switch block corresponding to the upper limit photoelectric switch and the lower limit photoelectric switch is fixedly installed on the part. 8 . The integrated two-degree-of-freedom manipulator according to claim 1 , wherein a number of reinforcing ribs are fixedly installed at the connection between the bottom plate and the rear side plate. 9. A control system for an integrated two-degree-of-freedom manipulator as claimed in any one of claims 1 to 8, wherein the control system includes: a computer, a controller connected to the computer, and a control The first driver and the second driver connected to the driver, the first driver is used to drive the servo motor, and the second driver is used to drive the hollow motor and receive position feedback information from the encoder to ensure the motion accuracy of the hollow motor. 10. The control system according to claim 9, wherein the controller drives the servo in a pulse manner, the number of pulses determines the number of rotations of the servo motor and/or the hollow motor, and the pulse frequency determines the servo motor and/or The rotational speed of the hollow motor.