Eddy current type robot zero point calibrator

Abstract

The utility model discloses an eddy current type robot zero point calibrator which is composed of a flat movable ruler and a fixed ruler, a metal reflector is arranged on the movable ruler, and two planar coils, a processing circuit and a battery are arranged on the fixed ruler. The movable ruler and the fixed ruler are installed at the two ends of a certain shaft of the robot respectively, and when the shaft rotates, the two coils generate different induction electric signals. And when the zero point is reached, the difference value of the induction electric signals of the two coils is zero, so that a zero point signal can be output to a robot controller, and zero point calibration is realized. The calibrator is small in size and small in occupied space, a lithium battery is arranged in the calibrator, a robot does not need to supply power to the calibrator, zero-point signals can be sent wirelessly, cables are not needed, and therefore the calibrator is very suitable for assembling of an existing robot and is also completely suitable for manufacturing of a new robot. And after each shaft of the robot is provided with a zero point calibrator, one-key zeroing can be finally realized.

Description

Technical Field

[0001] The utility model relates to a robot zero point calibrator, in particular to a robot zero point calibrator based on the eddy current grating principle. Background Art

[0002] Zero point refers to the mechanical origin of each axis of the robot, which is usually unchanged. All major brands of robots have so-called zero point identification points that can be seen at each axis or joint. Usually, an encoder reference value (such as 0°) can be specified for each axis of the robot at the mechanical zero point position, so each axis has a unique encoder angle value, which can represent the zero position of the robot.

[0003] The zero point is the initial position of the robot's operating model, and the zero point position is the reference for programming. Only with the mechanical origin can the robot's coordinate system be converted, and its motion trajectory be calculated and controlled. When the zero position is incorrect, the robot cannot move correctly. Only with a high-precision zero position can the robot's trajectory run normally. The robot will only work best when the zero point is fully and correctly calibrated. Only in this way can the robot achieve its highest point accuracy and trajectory accuracy. Moving the robot under uncalibrated conditions may cause personal injury or equipment damage.

[0004] The zero point of the robot is usually set at the factory and does not need to be adjusted under normal circumstances. Theoretically, when each axis reaches the zero position, the encoder count value is also zero. But in fact, when the encoder is zero, each axis is not at the mechanical zero position. There are many reasons for this, such as: the mechanical zero point of the robot changes during transportation, installation of a new machine, replacement and maintenance; the mechanical zero point of the robot changes after colliding with an interfering object during high-speed movement; the robot encoder loses power (battery), causing the zero point data of each axis of the robot to be lost; after the robot carries a load, the transmission and connecting arm will be affected by the load and deform.

[0005] To this end, it is usually necessary to calibrate the robot's zero point. Zero point calibration is to find the corresponding mechanical zero position for each axis and save the corresponding encoder position information in the system for the robot to use. If the robot axis is not zero-calibrated, the robot's functions will be severely limited: it cannot be programmed to run: it cannot run along the programmed points; it cannot translate in manual operation mode, it cannot move in the coordinate system; the software limit switch is closed.

[0006] At present, the method of robot soul and zero-point calibration is still relatively traditional, mainly using manual visual observation to see if the mechanical zero-position mark is aligned, which has low precision, low efficiency, high labor intensity, and cannot achieve automation and intelligence. Some companies use some mechanical measuring tools or electronic devices, which only replace the human eye to observe whether the zero position is aligned. It is still necessary to eliminate the installation, connection, debugging and other processes, which is still inefficient, slow and labor-intensive. Some scholars have proposed the use of visual methods to achieve zero-point detection, but it is expensive, bulky, and is bound to have the problem of partial axis occlusion, which is not practical. Summary of the invention

[0007] The utility model aims at the defects and shortcomings of the current robot field, such as the lack of zero-point calibration means, low efficiency, and low precision, and proposes an eddy current robot zero-point calibrator. The zero-point calibrator consists of a flat movable ruler and a fixed ruler. A metal reflector is arranged on the movable ruler, and two planar coils are arranged on the fixed ruler, as well as a processing circuit and a battery for power supply. The movable ruler and the fixed ruler are respectively installed at the two ends of a certain axis of the robot. When the axis rotates, the movable ruler moves relative to the fixed ruler, and the two coils will generate different induced electrical signals. When the zero point is reached, the induced electrical signals of the two coils are equal and the difference is zero, so that a zero-point signal can be output to the robot controller to achieve zero-point calibration. The calibrator required by the method is small in size and occupies little space. It has a built-in lithium battery and does not need to be powered by the robot. The zero-point signal can be sent wirelessly without cables, so it is very suitable for the assembly of existing robots and is also completely suitable for the production of new robots. After each axis of the robot is calibrated with a zero-point calibrator, "one-key zeroing" can be finally achieved. In addition, the zero point calibrator is an integrated measuring component with very low cost, which greatly reduces the application threshold, has high cost performance and good input-output ratio.

[0008] The utility model is realized by the following technical solutions:

[0009] The utility model provides an eddy current robot zero point calibrator, the calibrator is composed of a flat movable ruler and a fixed ruler, the movable ruler includes a movable ruler substrate and a reflector, the fixed ruler includes a fixed ruler substrate, a coil, a processing circuit, and a battery, wherein:

[0010] The movable ruler base plate is a plate-shaped piece made of light material, which is installed at the rotating end of a certain axis of the robot and rotates with it. Light material is used to reduce weight, and the plate-shaped shape reduces space occupation;

[0011] The reflector is a rectangular metal reflective conductor, which is placed at the center of the moving ruler substrate and generates eddy current effect under the electromagnetic field excitation of the coil, thereby realizing position detection;

[0012] The fixed-size base plate is a plate-shaped piece made of a lightweight material, which is installed at the other relatively fixed end of a certain axis of the robot. The lightweight material is used to reduce the weight, and the plate-shaped shape reduces the space occupied;

[0013] There are two coils, which are rectangular planar coils, located in the center of the fixed-size substrate and arranged symmetrically; the two coils have the same size and maintain a certain interval, which is not less than 10% of the total length of the two coils; the total length of the edges of the two coils is greater than or equal to the length of the reflector, and the width of the two coils is less than 90% of the width of the reflector;

[0014] The processing circuit is located on one side of the coil, and is used to provide excitation signals for the two coils, obtain the electrical signals output by the two coils, and perform data processing to finally obtain a zero-point signal, which is then transmitted via a wireless network.

[0015] The battery is a rechargeable lithium battery, which can provide power for the processing circuit on the one hand, and can be charged externally on the other hand to ensure long-term operation.

[0016] The working process of the eddy current robot zero point calibrator of the utility model is as follows: the processing circuit inputs an excitation signal to the left and right coils, and generates eddy currents in the reflector respectively, which in turn act on the left and right coils respectively, causing the electrical parameters of the two coils to change, and then generates an electrical signal output. The electrical signals output by the left and right coils are synchronously sent to the processing circuit for processing, and finally the zero point signal of the axis can be obtained.

[0017] The eddy current robot zero point calibrator is also characterized in that the processing circuit uses an intermittent power supply method to excite the two coils, that is, the two coils are excited during signal sampling and the two coils are stopped from being excited during data processing, so as to minimize the power consumption of coil excitation and extend the continuous working time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the composition of the eddy current zero point calibrator of the utility model;

[0019] Figure 2 It is a schematic diagram of the dimensions of the coil and reflector of the eddy current zero-point calibrator of the utility model;

[0020] In the figure, 1 is a movable ruler, 2 is a fixed ruler, 3 is a movable ruler substrate, 4 is a reflector, 5 is a fixed ruler substrate, 6 is a coil, 7 is a processing circuit, and 8 is a battery. DETAILED DESCRIPTION

[0021] The utility model is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the utility model. These all fall within the scope of protection of the utility model.

[0022] The utility model is realized by the following technical solutions:

[0023] The utility model provides an eddy current robot zero point calibrator, the calibrator is composed of a flat movable ruler 1 and a fixed ruler 2. The movable ruler 1 includes a movable ruler substrate 3 and a reflector 4, and the fixed ruler includes a fixed ruler substrate 5, a coil 6, a processing circuit 7, and a battery 8. Figure 1 As shown, where:

[0024] The movable ruler substrate 3 is a plate-shaped member made of a light material, such as a sample aluminum alloy material, so as to reduce weight and space occupation; the movable ruler substrate 3 is installed at the rotating end of a certain axis of the robot and rotates therewith;

[0025] The reflector 4 is a rectangular metal reflective conductor, such as copper, aluminum, etc.; the reflector 4 is placed at the center of the moving ruler substrate 3, and generates an eddy current effect under the electromagnetic field excitation of the coil 6, thereby realizing position detection;

[0026] The fixed-size substrate 5 is a plate-shaped member made of a light material, such as copper, aluminum, etc., so as to reduce weight and space occupation; the fixed-size substrate 5 is installed at the other relatively fixed end of a certain axis of the robot;

[0027] There are two coils 6, distributed 6a and 6b, which are rectangular planar coils, located in the center of the fixed-size substrate 5 and arranged symmetrically; the two coils 6a and 6b have the same size and maintain a certain interval, which is not less than 10% of the total length of the two coils; and the total length of the two coil edges 6a and 6b is greater than or equal to the length of the reflector 4, and the width of the two coils 6a and 6b is less than 90% of the width of the reflector 4. Figure 2 As shown;

[0028] The processing circuit 7 is located on one side of the coils 6a and 6b, and is used to provide excitation signals for the two coils 6a and 6b, and simultaneously obtain the electrical signals output by the two coils 6a and 6b, and perform data processing, and finally obtain a zero-point signal, and transmit it through a wireless network;

[0029] The battery 8 is a rechargeable lithium battery, which can provide power to the processing circuit 7 on the one hand, and can be charged externally on the other hand to ensure long-term operation.

[0030] The working process of the eddy current robot zero point calibrator of the utility model is as follows: the processing circuit 7 inputs an excitation signal to the left and right coils 6a and 6b, and generates eddy currents in the reflector 4, which in turn act on the left and right coils 6a and 6b, respectively, and cause the electrical parameters of the two coils 6a and 6b to change, thereby generating an electrical signal output. The electrical signals output by the left and right coils 6a and 6b are synchronously sent to the processing circuit 7 for processing, and finally the zero point signal of the axis can be obtained.

[0031] The eddy current robot zero point calibrator is also characterized in that the processing circuit 7 uses an intermittent power supply method to excite the two coils 6a and 6b, that is, the two coils 6a and 6b are excited during signal sampling, and the two coils 6a and 6b are stopped from being excited during data processing, so as to minimize the power consumption of the coils 6a and 6b excitation and extend the continuous working time.

[0032] Compared with the prior art, the utility model has the following beneficial effects:

[0033] (1) The eddy current robot zero point calibrator proposed in the utility model adopts the eddy current grating principle to detect the angle of the reflector, and judges the zero position signal by comparing the difference between the output signals of the left and right coils. Therefore, it has the remarkable characteristics of low power consumption, small size and low cost.

[0034] (2) The eddy current robot zero point calibrator proposed in the utility model adopts a flat shape and structure, which is not only small in size but also occupies less space and is very convenient to install, debug and maintain.

[0035] (3) The eddy current robot zero point calibrator proposed in the utility model has a built-in rechargeable lithium battery, which does not require power to be provided to the calibrator and is very suitable for installation on existing robots in service.

[0036] (4) The eddy current robot zero point calibrator proposed in the utility model adopts a wireless data transmission method, which completely eliminates the need for cables and provides the possibility for post-installation zero point calibration.

[0037] (5) The eddy current robot zero point calibrator proposed in the utility model can achieve the ideal goal of "one-button zeroing" after the calibrator is installed on each axis of the robot and cooperates with the corresponding calculation of the robot controller.

[0038] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention.

Claims

1. An eddy current robot zero point calibrator, the calibrator consists of a flat movable ruler and a fixed ruler, the movable ruler includes a movable ruler substrate and a reflector, and the fixed ruler includes a fixed ruler substrate, a coil, a processing circuit, and a battery, wherein: The movable ruler base plate is a plate-shaped piece made of a light material, which is installed at the rotating end of a certain axis of the robot and rotates with it; The reflector is a rectangular metal reflective conductor, which is placed at the center of the moving ruler substrate and generates eddy current effect under the excitation of the electromagnetic field of the coil; The fixed-size base plate is a plate-shaped piece made of a lightweight material and is installed at the other relatively fixed end of a certain axis of the robot; There are two coils, which are rectangular planar coils, located in the center of the fixed-size substrate and arranged symmetrically; the two coils have the same size and maintain a certain interval, which is not less than 10% of the total length of the two coils; the total length of the edges of the two coils is greater than or equal to the length of the reflector, and the width of the two coils is less than 90% of the width of the reflector; The processing circuit is located on one side of the coil, provides excitation signals for the two coils, obtains the electrical signals output by the two coils, performs data processing, and finally obtains the zero-point signal, which is transmitted via a wireless network; The battery is a rechargeable lithium battery, which can provide power for the processing circuit on the one hand, and can be charged externally on the other hand to ensure long-term operation.

2. The eddy current robot zero point calibrator according to claim 1, characterized in that: The processing circuit uses an intermittent power supply mode to excite the two coils, that is, the two coils are excited during the signal sampling period and the two coils are stopped from being excited during the data processing period, so as to reduce the power consumption of the coil excitation to the greatest extent and extend the continuous working time.

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