KR20200000044U - Integrated actuator using magnetic sensor - Google Patents

Abstract

The present invention relates to an integrated actuator using a magnetic sensor. A measuring mechanism for measuring at least one of an absolute angle and a relative angle associated with a rotating gear due to a motor of an aspect of the present invention, comprising: a magnet; And at least one of a magnitude and a direction of the magnetic field of the magnet, the magnetic sensor sensing that the magnetism of the magnet is changed by the rotation of the gear.

Description

Integrated actuator using magnetic sensor

The present invention relates to an integrated actuator using a magnetic sensor. Specifically, the present invention uses a plurality of magnetic sensors, a hollow magnetic encoder that does not require a multipole magnet or a precision gear, and a magnet capable of dramatically improving the performance and size of the product by combining the encoder with an integrated actuator. It relates to an integrated actuator using a sensor.

In the industry, monotonous repetitive tasks and potentially dangerous tasks are applied to robots to increase productivity, and people are relocated to more efficient tasks.

For example, a conveyor belt is installed at an assembly line in a factory, and necessary parts are transported. For the assembling process, it is necessary to unload the parts. This work has been manually performed by humans in the past, causing obstacles such as spinal compression.

In recent years, these tasks have been replaced by articulated robots, which greatly improves safety and productivity.

On the other hand, the joint of the robot is provided with a motor for applying torque as well as a reducer for increasing the torque of the motor, and a device for measuring the rotation angle of the joint.

However, conventionally, by applying a method of fabricating and assembling the above components, there is a disadvantage in miniaturization as well as generating errors during assembly.

In order to solve this problem, robot actuators incorporating the above-mentioned parts have recently been sold.

In case of using a motor-gear-encoder-integrated actuator, the robot joint can be easily manufactured.

Existing integrated actuators have a magnetic sensor mounted on-axis to measure the position of the output shaft, and the design method of the additional mechanism for mounting the magnetic sensor is preempted by some companies.

However, the current magnetic encoder technology is rapidly developing the off-axis method that enables the hollow shaft design rather than the on-axis method, and the development of the magnetic encoder technology using the off-axis method and the integrated actuator development equipped with the same Necessity is emerging.

Korean Patent Office Registration No. 10-1308738 Korean Patent Office Registration No. 10-2013-0045692

The present invention is to provide an integrated actuator using a magnetic sensor to solve the above problems.

Specifically, the present invention uses a plurality of magnetic sensors, a hollow magnetic encoder that does not require a multipole magnet or a precision gear, and a magnet capable of dramatically improving the performance and size of the product by combining the encoder with an integrated actuator. It is intended to provide a user with an integrated actuator using a sensor.

On the other hand, the technical problems to be achieved in the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned are clearly to those skilled in the art to which the present invention belongs from the following description. It can be understood.

In the measuring device for measuring at least one of the absolute and relative angles associated with the rotating gear due to a motor that is an aspect of the present invention for achieving the above technical problem, a magnet; And at least one of a magnitude and a direction of the magnetic field of the magnet, the magnetic sensor sensing that the magnetism of the magnet is changed by the rotation of the gear.

In addition, the magnet may be a bipolar magnet in cross section.

In addition, the magnetic sensor may be plural, and the plurality of magnetic sensors may be spaced apart from each other at predetermined intervals based on the magnet.

Further, the magnet is a circular cross-section dipole magnet, the magnetic sensor is plural, and the plurality of magnetic sensors are arranged to be spaced apart at predetermined intervals adjacent to the circular cross-section dipole magnet, thereby It is possible to compensate for the distortion of the value changing by the rotation.

In addition, the measuring device may be applied to the hollow actuator.

On the other hand, an actuator of another aspect of the present invention for achieving the above technical problem, a motor, a gear that rotates due to the motor; A gear box connected to the gear; And a measuring device inserted into at least a portion of the gearbox and measuring at least one of an absolute angle and a relative angle associated with the gear rotating by the motor.

In addition, the gear is a plurality, the input case connected to the motor (2); A first internal gear 5 connected to the input side case 2 of the plurality of gears; An eccentric shaft (3) fixedly connected to the outer gear (4) and the input side case (2) of the plurality of gears, the one end being engaged with the first inner gear (5) and rotating; A second inner gear 7 engaged with the other end of the eccentric shaft 3 of the plurality of gears and rotating together; An output unit 6 for outputting a force transmitted to the second internal gear 7; And an output case 8 having a bearing 9 through which the output unit 6 passes.

In addition, at least some of the input case 2, the first internal gear 5, the second internal gear 7, the output unit 6, and the gearbox and the measuring device may be integrally manufactured.

In addition, at least some of the eccentric shaft 3, the outer gear 4, the output unit 6, the gear box and the measuring mechanism may be manufactured in a hollow form.

The present invention can provide a user with an integrated actuator using a magnetic sensor.

Specifically, the present invention uses a plurality of magnetic sensors, a hollow magnetic encoder that does not require a multipole magnet or a precision gear, and a magnet capable of dramatically improving the performance and size of the product by combining the encoder with an integrated actuator. An integrated actuator using a sensor can be provided to the user.

On the other hand, the effect that can be obtained in the present invention is not limited to the above-mentioned effects, other effects that are not mentioned will be clearly understood by those skilled in the art from the following description. Could be.

Figure 1 shows an example of a conventional cycloidal gear associated with the present invention.
FIG. 2 illustrates an example of a structure in which a separate sensor support is installed at an output unit and a position is measured using a sensor such as a magnetic encoder.
FIG. 3 illustrates an example in which the structure shown in FIG. 2 is improved to drill holes through the reducer and the shaft, and a rotating rod is installed inside the hollow shaft.
Figure 4 shows an example of an integrated actuator using a micro cycloidal reducer in connection with the present invention.
FIG. 5 is a diagram for describing an on-axis method and an off-axis method in relation to a magnetic sensor.
6 is a view for explaining the operation of the integrated actuator according to the present invention.
7A to 7C illustrate an example of an integrated actuator equipped with an on-axis magnetic sensor according to the present invention.
8 illustrates a structure using a conventional hollow shaft or spur gear and an integrated actuator structure using a magnetic sensor proposed by the present invention.
9 and 10 illustrate an integrated actuator using a magnetic sensor proposed by the present invention.
11 shows an example of a hollow actuator proposed by the present invention.

In the industry, monotonous repetitive tasks and potentially dangerous tasks are applied to robots to increase productivity, and people are relocated to more efficient tasks.

The joint of the robot is provided with a motor for applying torque, a speed reducer for increasing the torque of the motor, and a device for measuring the rotation angle of the joint.

However, conventionally, by applying a method of fabricating and assembling the above components, there is a disadvantage in miniaturization as well as generating errors during assembly.

In order to solve this problem, robot actuators incorporating the above-mentioned parts have recently been sold.

In case of using a motor-gear-encoder-integrated actuator, the robot joint can be easily manufactured.

Figure 1 shows an example of a conventional cycloidal gear associated with the present invention.

Referring to FIG. 1, the conventional cycloidal gear 100 uses the inner circumferential surface of the case as an internal gear 30 and two external gears 40 and 50 to contact the internal gear 30. It is installed in each groove penetrating through the external gears (40, 50) using a plurality of output pins (Output pins, 60) to combine with the output carrier (Output carrier, 70) requires a complex manufacturing / assembly process It was disadvantageous.

In addition, since the rotation angle of the reducer output unit 70 corresponds to the rotation angle of the robot joint, a measurement method for this should be provided.

2 is a view illustrating an example of a structure in which a separate sensor support is installed in an output unit and a position is measured by using a sensor such as a magnetic encoder.

Referring to FIG. 2, an additional sensor support 210 may be installed at the output unit 70, and the position may be measured by using a sensor 130a such as a magnetic encoder.

However, the structure of FIG. 2 is not only impossible to rotate 360 degrees of the joint due to the structure 210 for supporting the sensor 130a, but also increases the axial length so that the design mat is less suitable for use in an articulated robot having an axial coincidence structure. There was a serious problem.

Prior art for solving this problem is described in Korean Patent Laid-Open Publication No. 10-2013-0045692, with reference to FIG.

FIG. 3 illustrates an example in which the structure shown in FIG. 2 is improved to drill holes through the reducer and the shaft, and a rotating rod is installed inside the hollow shaft.

Referring to FIG. 3, a hole penetrating the reducer 90 and the shaft 220 should be installed, and a rotating rod should be installed inside the hollow shaft.

However, since the hollow shaft must be used in the structure as shown in FIG. 3, the stiffness of the shaft is weakened in the same manner as the conventional hollow actuator, and the inside of the hollow shaft is connected to the wiring due to the rotation rod installed therein. The benefits to be used have also been lost.

In addition, Figure 4 shows an example of an integrated actuator using a micro cycloidal reducer proposed by the present invention.

Referring to FIG. 4, the ultra-small cycloid reducer included in the proposed actuator has a structure different from the structure of the cycloid reducer applied to the conventional actuator, for example, FIG. 1.

Specifically, according to the present invention, the eccentric shaft 3 is fixed to the input side case 2 connected with the motor 1 by a bearing, and the eccentric shaft 3 is similarly bearing to the outer gear 4 composed of two stages. Secure with.

Further, the first stage and the second stage of the external gear 4 are rotated in engagement with the internal gear 1 (5) attached to the input side case 2 and the internal gear 2 (7) attached to the output section 6, respectively. The output part 6 with 2 (7) attached penetrates through the cross roller bearing 9 fixed to the output side case 8.

In this case, in order to further reduce the frictional force of the gears, a pin roller bearing may be additionally added between the outer gear 4 and the inner gear 1 (5) engaged with each other, or between the outer gear and the inner gear 2 (7).

Therefore, unlike the conventional structure of FIG. 1 described above, the structure of the present invention proposed in FIG. 4 does not require a plurality of output pins to penetrate the plate gear, thereby simplifying the assembly and miniaturizing the size.

On the other hand, the encoder applied to the above-mentioned actuators include a rotary encoder, an optical encoder, a magnetic encoder and the like.

Rotary encoders are angle sensors that convert mechanical displacements in the rotational direction into digital signals. Recently, rotary encoders are used in applications requiring precise measurement of the speed / position of rotating parts for high performance control of machine tools or robots.

In addition, the optical encoder uses a disk having a slit arranged at regular intervals on the rotation axis and a light detector (light emitting portion and light receiving portion).

In this case, when the light of the light emitting part passes through the slit engraved in the disk and reaches the light receiving part, the light may be divided into an incremental type and an absolute type according to the shape of the slit by outputting a pattern of the disk.

Absolute optical encoder not only increases the number of output signal lines, but also has a disadvantage in that the size of the disk is relatively large.

As an alternative, a magnetic encoder using the following magnetic sensor can be used.

The magnetic encoder can detect the position of the rotating shaft in various ways depending on the type of magnetic sensor or magnet used.

Hall sensors and magnetoresistances are used for the types of magnetic sensors. Recently, semiconductor integrated technologies have been applied and are also sold in the form of semiconductor IC devices.

FIG. 5 is a diagram for describing an on-axis method and an off-axis method in relation to a magnetic sensor.

Referring to Figure 5, the installation method of the magnetic sensor is divided into an on-axis method for installing the sensor in the center of the rotation axis and an off-axis method for installing at a distance away from the center of the rotation axis.

Referring to FIG. 5, the off-axis method may use a hollow rotating shaft because the magnetic sensor is installed at a distance away from the rotating shaft to measure the rotation angle. However, it is known that the distortion and noise of the measurement signal are relatively increased compared to the on-axis method.

6 is a view for explaining the operation of the integrated actuator according to the present invention.

Referring to (a) to (c) of Figure 6, the motor can be implemented in DC / BLDC / PMSM, the gear can be implemented in Harmonic gear / Cycloid gear / Planetary gear.

In addition, the position measuring sensor (encoder) is used, the input shaft relative position (Incremental) encoder can be implemented with a high resolution for driving the motor, the output absolute position encoder (Absolute) encoder is used to measure the rotation angle of the robot joint .

Existing integrated actuator is equipped with magnetic sensor mainly on-axis for measuring output shaft position, and additional mechanism design method for magnetic sensor mounting is being developed together.

On the other hand, the proposed method has the advantage of miniaturization and hollow design compared to the existing integrated actuator by applying the off-axis method, and the disadvantage of the off-axis method (signal distortion) is that many magnetic sensors Use to overcome.

Prior to the detailed description of the present invention, an integrated actuator equipped with an on-axis magnetic sensor will be described.

7A to 7C illustrate an example of an integrated actuator equipped with an on-axis magnetic sensor according to the present invention.

Referring to FIG. 7A, magnetic sensors 343b and 353b are installed on the rotation shafts of two spur gears 340 and 350 for installing a plurality of spur gears and combining the gear ratios of the spur gears to maintain a 1: 1 rotation ratio with the output shaft. The on-axis way of installing the components is shown.

The structure shown in FIG. 7A has an advantage in the hollow design but has a disadvantage in that the weight increase and the structure are complicated due to the use of multiple spur gears.

In addition, referring to FIG. 7B, an on-axis method of installing a hollow shaft penetrating a gear and penetrating a rotating rod inside the hollow shaft to install a magnetic sensor at an end of the rotating rod 600 is illustrated.

The structure shown in FIG. 7B is a unique way of using the interior of a two-stage cycloidal gear that is easy to hollow design, but has the disadvantage that the hollow design is not possible due to the installation of the rotating rod.

In addition, referring to FIG. 7C, a portion of the microcycloidal speed reducer is molded into a spur gear shape 10, and an absolute angle or a relative angle is detected on the side of another spur gear 11 engaged therewith. An angle detection unit, in which a magnetic encoder 12 and a magnet 13 are provided, is shown.

The method shown in FIG. 7c can thus be seen as a method of shaping part of the power transmission structure together at the output 6 of the cycloidal speed reducer.

That is, FIG. 7C shows an on-axis method in which a spur shape is formed on an output member of a cycloidal gear and a magnetic sensor is installed on a rotation shaft of a spur gear having a 1: 1 rotation ratio with the output shaft.

Here, the axial length is reduced and the hollow design has the advantage of being possible, but there is a disadvantage that the position measurement error may occur due to the spur shape of the output member for power transmission and the wear of the spur gear.

As described with reference to FIGS. 7A to 7C, despite the disadvantage of requiring an additional mechanism (gear, rotating rod), an on-axis method rather than an off-axis method is used.

In other words, in the case of the off-axis method using a multipole magnet, the manufacture of a multipole magnet is relatively difficult compared to a two pole magnet in cross section, and the absolute position detection is difficult. .

N-pole and S-pole are arranged in a special form, and two ring magnets having phase differences are difficult to manufacture, and absolute position detection is difficult.

In addition, although there is an off-axis method using a single-sided bipolar magnet, there is a problem in that a relatively complex signal processing method is required to overcome harmonic errors and nonlinearities caused by the separation distance from the magnet.

As a result, in the current state, we have developed a hollow magnetic encoder that does not require multipole magnets or precision gears by using multiple magnetic sensors, which are the main causes of the price increase, and combined with integrated actuators to dramatically improve product performance and size. We need an improved product.

Therefore, the present invention is to provide an integrated actuator using a magnetic sensor to solve the above problems.

Specifically, the present invention uses a plurality of magnetic sensors, a hollow magnetic encoder that does not require a multipole magnet or a precision gear, and a magnet capable of dramatically improving the performance and size of the product by combining the encoder with an integrated actuator. It is intended to provide a user with an integrated actuator using a sensor.

8 shows a structure using a conventional hollow shaft or spur gear and an integrated actuator structure using a magnetic sensor proposed by the present invention.

Referring to (a) and (b) of FIG. 8, as a method using an additional mechanism and an on-axis magnetic sensor, a method using a hollow shaft and a method using a spur gear are shown.

In addition, referring to FIG. 8C, as a structure proposed by the present invention, a method of using a signal processing algorithm, a single-sided bipolar magnet 3400, and a plurality of off-axis magnetic sensors 3600 is illustrated.

9 and 10 illustrate an integrated actuator using a magnetic sensor proposed by the present invention.

9 and 10, the Off-axis scheme proposed by the present invention is expected to be able to replace the existing On-axis scheme sufficiently because it can solve the above disadvantages.

Specifically, the proposed method overcomes the limitations of the off-axis method using a plurality of magnetic sensors 3600.

9, the features of the proposed structure and method are as follows.

First, it uses a single-sided bipolar magnet 3400.

Since the multipole magnet is manufactured using a magnet yoke of a relatively complicated shape compared to the single-sided bipolar magnet 3400, it is not only difficult to produce but also requires a special type of pole arrangement for absolute position measurement.

On the other hand, the single-sided bipolar magnet 3400 is relatively easy to manufacture and easy to measure the absolute position can greatly increase the productivity and price competitiveness of the product.

Next, in the present invention, the signal processing unit is used. In the case of using the single-sided bipolar magnet 3400, the output of the sensor perpendicular to the magnetic flux is weak, so that the measurement error is generated and the signal is distorted due to noise. It can solve the problem.

That is, the method proposed by the present invention is to apply a signal processing technique that can compensate for the distortion of the signal by arranging a plurality of magnetic sensors 3600 around the magnet 3400 at specific intervals.

In addition, the present invention may be applied to an embodiment in which the magnetic sensor 3600 is additionally used to sense information by placing the magnetic sensor 3600 at an input terminal instead of an output terminal.

In addition, the sensor disposed at the input terminal may be used in addition to the magnetic sensor 3600, another kind of sensor (such as an optical sensor) capable of sensing the movement of the input terminal.

Finally, the present invention is characterized in that it can be manufactured in a hollow design.

That is, since the additional mechanism (rotating rod, gear, etc.) mentioned in Figures 7a to 7c is not necessary, the weight and design complexity of the product can be greatly reduced.

In particular, when mounted on the integrated actuator, the magnetic sensor 3600 and the ring magnet 3400 is directly installed on the output shaft to enable a hollow design of compact size.

For example, in FIG. 9, the rotation angle measuring method of the input shaft is illustrated in the on-axis method in the same manner as the conventional method, but this may be excluded or may be mixed with other methods. phrase

Specifically, an embodiment of a compact hollow actuator to which the proposed method is applied is shown in FIG.

Therefore, the present invention can provide a user with an integrated actuator using a magnetic sensor.

Specifically, the present invention uses a plurality of magnetic sensors, a hollow magnetic encoder that does not require a multipole magnet or a precision gear, and a magnet capable of dramatically improving the performance and size of the product by combining the encoder with an integrated actuator. An integrated actuator using a sensor can be provided to the user.

Embodiments of the present invention described above may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

In the case of a hardware implementation, the method according to embodiments of the present invention may include one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), and Programmable Logic Devices (PLDs). It may be implemented by field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, procedure, or function that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

Detailed description of the preferred embodiments of the present invention disclosed as described above is provided to enable those skilled in the art to implement and practice the present invention. Although described above with reference to preferred embodiments of the present invention, those skilled in the art will understand that the present invention can be variously modified and changed within the scope without departing from the scope of the present invention. For example, those skilled in the art can use each of the configurations described in the above-described embodiments in combination with each other. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be interpreted as limiting in all aspects and should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention. The present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. In addition, the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship or may be incorporated as new claims by post-application correction.

Claims (1)

motor;
A gear that rotates due to the motor;
A gear box connected to the gear; And
And a measuring mechanism according to claim 1 inserted into at least a portion of the gearbox and measuring at least one of an absolute angle and a relative angle associated with the gear that rotates due to the motor.

The measuring mechanism,
magnet; And
And at least one of a magnitude and a direction of a magnetic field of the magnet, the magnetic sensor measuring that the magnetism of the magnet is changed by the rotation of the gear.
The magnet is a circular cross-section dipole magnet,
The magnetic sensor is plural,
The plurality of magnetic sensors are arranged to be spaced apart at predetermined angles adjacent to the circular cross-section dipole magnets, thereby compensating for distortion of a value changed by rotation of the gear,

The gear is plural,
An input case 2 connected to the motor;
A first internal gear (5) connected to the input side case (2) of the plurality of gears;
An eccentric shaft (3) fixedly connected to the outer gear (4) and the input side case (2) of the plurality of gears, the one end being engaged with the first inner gear (5) and rotating;
A second internal gear (7) which meshes with the other end of the eccentric shaft (3) and rotates together among the plurality of gears;
An output unit 6 for outputting a force transmitted to the second internal gear 7; And
And an output case 8 having a bearing 9 through which the output part 6 passes.

At least some of the input case 2, the first internal gear 5, the second internal gear 7 and the output unit 6, the gear box and the measuring mechanism are made in one piece,

At least some of the eccentric shaft (3), the external gear (4), the output unit (6), the gearbox and the measuring mechanism are manufactured in a hollow form.

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