A rotating sample positioning device without position sensor and positioning method thereof

Abstract

The present invention discloses a rotating sample position positioning device without position sensor and a positioning method thereof. The positioning device comprises a turntable and a mechanical arm. The turntable is provided with sample positions. The sample positions are arranged circumferentially along the radius r with the center of the turntable as the center. The sample positions are arranged in sequence along a clockwise direction starting with the zeroth sample position. The polarity of the magnet on the zeroth sample position is different from the polarity of the magnet on other sample positions. The mechanical arm is provided with a magnetic sensor. The positioning method uses the polarity of the magnet to distinguish the number of the sample position. The beneficial effects of the present invention are as follows: the positioning of the rotating object position is realized without the need for expensive servo systems and position, angle sensors, and visual positioning and recognition systems; the mechanical arm does not need to know the coordinate points of each position in advance, and can automatically search and locate relatively quickly; the function of identifying the position "number" is realized at a very low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of equipment workpiece positioning, and specifically relates to a rotating sample position positioning device without a position sensor and a positioning method thereof, after a number of designated positions are rotated around a known central axis to any position without the aid of a rotation position sensor. Background Art

[0002] In automated production equipment and instruments, objects often need to be placed on a rotating mechanism for operations such as transporting and filling objects. After rotating at any angle, the robot arm needs to locate, identify, and grab the rotated objects.

[0003] For example, in a centrifugal drying mechanism, each item has a unique number, and when loading, it is necessary to record which sample position each item is placed on the turntable. After high-speed rotation, the turntable will randomly stop at a certain position. At this time, a robotic arm is required to locate each sample position for grabbing, and grab the item at that position to the specified position. The order of the items cannot be out of order.

[0004] In traditional technical solutions, the final stop position is achieved by precisely controlling the motor rotation angle, or installing position and rotation angle sensors such as photoelectric / magnetic encoders and photoelectric positioning switches on the rotating shaft.

[0005] The only way to achieve rotational positioning by precisely controlling the rotation of the motor is to use stepper motors and servo control systems. Stepper motors cannot meet the requirements of high-speed rotation, and the maximum speed of the mainstream servo control system is only <4000rpm. In addition, the price, power consumption, and volume parameters are relatively large, making it difficult to achieve high cost-effectiveness, compactness, and lightness of the product.

[0006] The method of using position or rotation angle sensors requires precise installation of sensors, generally requires the use of absolute position sensors, and also requires complex software and hardware algorithms and equipment implementation. The assembly and debugging cycle is long and the cost is high.

[0007] If the rotation position may change frequently, such as when testing the production process, it is necessary to constantly adjust the placement of the object on the rotating disk in order to obtain the optimal process parameters. Each change in placement requires re-updating the relevant software and the robot arm grasping position parameters, which is very inconvenient and cumbersome. Summary of the invention

[0008] The purpose of the present invention is to provide a rotating sample positioning device without a position sensor and a positioning method thereof, which solves the problem of cumbersome and complicated positioning of objects on a rotating mechanism.

[0009] The object of the present invention is achieved through the following technical solutions:

[0010] A rotating sample position positioning device without a position sensor comprises a turntable and a mechanical arm. The turntable is provided with at least two sample positions. The sample positions are arranged circumferentially along a radius r with the center of the turntable as the center. The sample positions are arranged in sequence along a clockwise direction starting with the zeroth sample position. The polarity of the magnet at the zeroth sample position is different from the polarity of the magnets at other sample positions. The mechanical arm is provided with a magnetic sensor.

[0011] Furthermore, the turntable is rotatably arranged via a central axis, and the central axis is arranged concentrically with the turntable.

[0012] Furthermore, the magnet on the sample position is arranged axially.

[0013] Furthermore, the sample positions include a zeroth sample position, a first sample position, a second sample position, a third sample position and a fourth sample position.

[0014] Furthermore, the magnetic sensor is a one-dimensional or three-dimensional Hall device.

[0015] A positioning method of the above positioning device comprises the following steps:

[0016] a. The robot moves to the center of the turntable according to the known coordinates of the center of the turntable;

[0017] b. The robot moves a distance r along any radial direction;

[0018] c. The robotic arm moves around the center of the turntable with a radius of r in the clockwise direction of the sample position arrangement, and uses a magnetic sensor to detect the magnetic field strength and direction;

[0019] d. When the magnetic sensor detects the polarity of the zeroth sample position and the magnetic induction intensity reaches a maximum value, it moves to point P just above the zeroth sample position, stops subsequent movement and records the position information;

[0020] e. The robot continues to search for the first sample position along the clockwise direction;

[0021] f. When the magnetic sensor detects the opposite polarity of the next zeroth sample position and the magnetic induction intensity is a maximum value, it moves to the top of the next sample position;

[0022] g. Repeat step f to position the next sample in sequence until all steps are completed.

[0023] Furthermore, in step e, the robot moves to point P, the manipulator of the robot arm grabs the zeroth sample, returns to point P, and then the robot arm continues searching; in step f, when it moves to the top of the next sample position, it can grab the sample at that position, and finally returns to that position.

[0024] Functions achieved by the present invention:

[0025] 1. It can realize the positioning of the rotation position at low cost by using only ordinary position sensorless motor and rotation angle sensor, and can identify the "number" of each position.

[0026] 2. The robotic arm has the ability to automatically search and identify sample locations.

[0027] 3. The complete set of equipment has high cost performance and is convenient for mass production and assembly.

[0028] Beneficial effects of the present invention:

[0029] 1. No expensive servo system and position, angle sensing, or visual positioning recognition system is required to realize the positioning of rotating objects.

[0030] 2. The robot arm does not need to know the coordinates of each position in advance, and can automatically search and locate quickly.

[0031] 3. The function of identifying location "number" is realized at a very low cost.

[0032] The aforementioned main scheme of the present invention and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection by the present invention; and in the present invention, (non-conflicting options) options and other options can also be freely combined. After understanding the scheme of the present invention, those skilled in the art can understand that there are many combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present invention, and they are not exhaustively listed here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of a turntable of the present invention.

[0034] Figure 2 Schematic diagram of the robot arm of the present invention.

[0035] In the figure: 1-turntable, 2-central axis, 3-mechanical arm, 4-magnetic sensor; 10-zeroth sample position, 11-first sample position, 12-second sample position, 13-third sample position, 14-fourth sample position. DETAILED DESCRIPTION

[0036] The following non-limiting examples serve to illustrate the invention.

[0037] Embodiment 1:

[0038] refer to Figure 1 and Figure 2As shown, a rotating sample positioning device without position sensor comprises a turntable 1 and a mechanical arm 3. The turntable 1 is arranged to rotate through a central axis 2, and the central axis 2 is arranged concentrically with the turntable 1. The turntable 1 uses the central axis 2 as a rotation axis and performs rotational motion around the axis.

[0039] The turntable 1 is provided with five sample positions, including a zeroth sample position 10 , a first sample position 11 , a second sample position 12 , a third sample position 13 and a fourth sample position 14 .

[0040] The sample positions are arranged circumferentially with the center of the central axis 2 and along a known radius r. The sample positions are arranged in sequence along a clockwise direction starting with the zeroth sample position 10. Each position can be numbered clockwise or counterclockwise. In this embodiment, they are numbered in the counterclockwise direction, that is, the positions in the counterclockwise direction of the zeroth sample position are numbered first, second, third... and so on.

[0041] Each sample position has a magnet arranged axially, and in particular, the polarity of the magnet on the zeroth sample position 10 is different from the polarity of the magnets on other sample positions, and the polarities of the magnets on other sample positions are the same. For ease of description, in this embodiment, the zeroth sample position uses an N pole, and the other sample positions use an S pole.

[0042] A magnetic sensor 4 is provided at the top of the robot arm 3. The magnetic sensor 4 is a one-dimensional or three-dimensional Hall device. The robot arm 3 needs to have the ability to automatically search and identify the sample position, that is, the control unit determines the position of the sample position by the magnetic induction intensity and distinguishes the number of the position.

[0043] The relative position of the robotic arm and the magnetic sensor is known and fixed, that is, when the magnetic sensor successfully locates a sample position, the robotic arm is installed with fixed parameters to perform relative movement, so that the mechanical claw and the object can be aligned to implement object grasping.

[0044] Embodiment 2:

[0045] In a positioning method of the above positioning device, the position information of the center axis of the turntable needs to be "informed" to the robot arm in advance. Each time the robot arm searches and locates the sample position, it starts with the center axis position. At the same time, all sample positions must be located on the same circle, and the radius r from the center axis is known. In this way, when the turntable stops randomly after rotating at any angle, the robot arm locates and identifies each sample position according to the following steps:

[0046] a. The robot arm 3 moves to the center of the central axis 2 according to the known coordinates of the center of the turntable 1, that is, the coordinates of the center of the central axis 2.

[0047] b. The robot arm 3 moves a distance r along any radial direction, and is now located on the circle where all sample positions are located.

[0048] c. The robot arm 3 moves in a counterclockwise direction around the center of the turntable 1 with a radius r, and uses the magnetic sensor 4 to detect the magnetic field strength and direction in real time.

[0049] d. After the robot arm completes the 360-degree movement, it will inevitably pass through all sample positions. When the magnetic sensor 4 detects the polarity N of the zeroth sample position 10 and the magnetic induction intensity is at a maximum value, it moves to point P just above the zeroth sample position 10, stops the subsequent movement and records the position information.

[0050] e. After the manipulator of the robot arm 3 grabs the zeroth sample, it returns to point P, and then the robot arm 3 continues to search for the first sample position in the counterclockwise direction.

[0051] f. When the magnetic sensor 4 detects the first polarity S and the magnetic induction intensity reaches a maximum value, it moves to the top of the first sample position 11, stops the subsequent movement and records the position information, then the first sample can be grabbed, and finally returns to this position.

[0052] When the magnetic sensor 4 detects the next polarity S and the magnetic induction intensity reaches a maximum value, it has moved to the top of the next sample position, stops the subsequent movement and records the position information, then the sample can be grabbed and finally returns to the position.

[0053] g. Repeat step f to position the next sample in sequence until all steps are completed.

[0054] It should be noted that the turntable must be kept stationary when performing the above operations. Generally, motors have a certain holding torque, so it is easier to meet this condition.

[0055] The above basic examples of the present invention and their further optional examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed for protection by the present invention. In the scheme of the present invention, each optional example can be arbitrarily combined with any other basic examples and optional examples.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A positioning method for a rotating sample positioning device without a position sensor, characterized in that: The positioning device comprises a turntable (1) and a mechanical arm (3), wherein the turntable (1) is provided with at least two sample positions, the sample positions are arranged circumferentially along a radius r with the center of the turntable (1), the sample positions are arranged in sequence along a clockwise direction starting with the zeroth sample position (10), the polarity of the magnet on the zeroth sample position (10) is different from the polarity of the magnets on the other sample positions, and the mechanical arm (3) is provided with a magnetic sensor (4); The following steps are also included: a. The robot arm (3) moves to the center of the turntable (1) according to the known coordinates of the center of the turntable (1); b. The robot arm (3) moves a distance r along any radial direction; c. The robot arm (3) moves around the center of the turntable (1) with a radius r in the clockwise direction of the sample position arrangement, and uses the magnetic sensor (4) to detect the magnetic field strength and direction; d. When the magnetic sensor (4) detects the polarity of the zeroth sample position (10) and the magnetic induction intensity reaches a maximum value, it moves to point P just above the zeroth sample position (10), stops the subsequent movement and records the position information; e. The robot arm (3) continues to search for the first sample position along the clockwise direction; f. When the magnetic sensor (4) detects the opposite polarity of the next zeroth sample position (10) and the magnetic induction intensity reaches a maximum value, it moves to the top of the next sample position; g. Repeat step f to position the next sample in sequence until all steps are completed.

2. The positioning method according to claim 1, characterized in that: In step e, the robot moves to point P, the manipulator of the robot arm (3) grasps the zeroth sample, and then returns to point P, and then the robot arm (3) continues searching; in step f, when it moves to the top of the next sample position, it can grasp the sample at that position, and finally returns to that position.

3. The positioning method according to claim 1, characterized in that: The turntable (1) is arranged to rotate via a central axis (2), and the central axis (2) is arranged concentrically with the turntable (1).

4. The positioning method according to claim 1, characterized in that: The magnet on the sample position is arranged axially.

5. The positioning method according to claim 1, characterized in that: The magnet is a magnet.

6. The positioning method according to claim 1, 4 or 5, characterized in that: The sample positions include a zeroth sample position (10), a first sample position (11), a second sample position (12), a third sample position (13) and a fourth sample position (14).

7. The positioning method according to claim 1, 4 or 5, characterized in that: The magnetic sensor (4) is a one-dimensional or three-dimensional Hall device.

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