Centrifugal machine positioning control method

Abstract

The invention relates to a centrifugal machine positioning control method. The method comprises the following steps that S1, the positioning position and the positioning target angle of a rotor are determined; s2, detecting the real-time angle of the rotor; s3, calculating the absolute value of the difference between the real-time angle of the rotor and the angle of the positioning target, judging whether the absolute value is greater than a first preset value, and executing S6 if the absolute value is less than or equal to the first preset value; s4, starting and driving the rotor to rotate slowly according to a preset energy value; s5, judging whether the absolute value of the angle difference is greater than a second preset value, and if the absolute value is less than or equal to the second preset value, controlling the rotor to quickly hover and then executing S3; otherwise, executing S4; s6, controlling the output energy of the centrifugal machine to be 0; s7, positioning is carried out; s8, calculating the absolute value of the angle difference value, judging whether the absolute value is greater than a third preset value, and finishing positioning if the absolute value is less than or equal to the third preset value; otherwise, executing S2. According to the invention, by giving preset energy and detecting the real-time angle of the rotor, closed-loop control is formed, and accurate positioning of the rotor is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of centrifuge positioning, and in particular relates to a centrifuge positioning control method. Background Art

[0002] A centrifuge is a device that uses centrifugal force to separate liquid suspensions of different densities and particle sizes. The sample is placed in the centrifuge rotor. The rotor is mounted on top of the motor shaft.

[0003] At present, positioning centrifuges are widely used in the fields of petroleum, chemical, pharmaceutical, food and sample testing automation. Especially in the pre-processing automation application of sample testing, the requirements for sample centrifugal processing efficiency are getting higher and higher, among which the positioning accuracy and stability of the rotor cup after each centrifugation is one of the key indicators. The existing high-cost solution of customizing high-performance servo motors and positioning mechanisms can meet the positioning accuracy and stability indicators, but this solution is expensive, and most of the customized high-performance servo motors are imported brands, and the maintenance cost is also high, which is not conducive to the large-scale promotion and application of such pre-processing automation applications.

[0004] In summary, there is an urgent need to provide a cost-saving centrifuge positioning control method that can replace the existing general positioning method of customizing high-cost servo motors. Summary of the invention

[0005] The object of the present invention is to provide a centrifuge positioning control method which is cost-saving and can replace the existing general positioning method of custom-made high-cost servo motors.

[0006] The above object is achieved through the following technical solution: A centrifuge positioning control method, comprising the following steps:

[0007] S1, determining the positioning position and positioning target angle of the centrifuge rotor;

[0008] S2, detecting the real-time angle of the centrifuge rotor;

[0009] S3, calculate the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and determine whether it is greater than a first preset value. If it is less than or equal to the first preset value, execute step S6; if it is greater than the first preset value, execute step S4.

[0010] S4, starting the centrifuge to drive the rotor to rotate slowly according to the preset energy value and continuously detecting the real-time angle of the centrifuge rotor;

[0011] S5, calculating the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and judging whether it is greater than a second preset value, if it is less than or equal to the second preset value, controlling the centrifuge rotor to hover quickly and then executing step S3; if it is greater than the second preset value, executing step S4;

[0012] S6, controlling the centrifuge output energy to 0, and the centrifuge rotor is in a free stop state;

[0013] S7, controlling the guide rod of the positioning mechanism to extend to position the centrifuge rotor;

[0014] S8, calculate the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and determine whether it is greater than a third preset value. If it is less than or equal to the third preset value, the positioning is completed; if it is greater than the third preset value, execute step S2.

[0015] The present invention is used for positioning a high-speed centrifuge after completing a centrifugal operation. In a specific application, a presettable energy is given to control the centrifuge rotor to rotate slowly, and the real-time angle of the rotor is detected to form a closed-loop control. The fuzzy rough positioning of the centrifuge rotor is first realized, and then the guide rod of the positioning mechanism is extended to accurately guide and fix the centrifuge rotor, thereby realizing the precise positioning of the centrifuge rotor.

[0016] A further technical solution is that the positioning mechanism is provided with a first position sensor for detecting the extended position of the guide rod, and in step S7, the driving member of the positioning mechanism is first started to drive the guide rod to extend, and when the signal of the position sensor is detected, the positioning driving member is controlled to stop moving.

[0017] A further technical solution is that the positioning mechanism is provided with a second position sensor for detecting the return position of the guide rod, and the step S2 also includes the step of detecting whether the guide rod has returned: detecting the signal of the second position sensor, if the signal of the second position sensor is not detected, then controlling the driving member of the positioning mechanism to drive the guide rod to retract, until the signal of the second position sensor is detected, then controlling the positioning driving member to stop moving.

[0018] A further technical solution is that, before step S1, a step of locating the zero angle position of the centrifuge rotor is also included, and the angle between the located position of the centrifuge rotor and the zero angle position is the positioning target angle.

[0019] A further technical solution is that after the step S6 is executed, there is a delay of a predetermined time before executing the step S7.

[0020] A further technical solution is that the positioning end of the guide rod is in the shape of a semi-spherical head, and a conical guide hole is provided at the bottom of the hanging cup at the positioning position of the centrifuge rotor. In the step S7, the guide rod is controlled to extend upward, and during the extension process, the positioning end of the guide rod cooperates with and is inserted into the conical guide hole at the bottom of the hanging cup at the positioning position of the centrifuge rotor.

[0021] A further technical solution is that the positioning mechanism is provided with a guide sleeve, the guide rod passes through the guide sleeve, and the guide rod is guided by the guide sleeve when moving vertically.

[0022] Compared with the prior art, the present invention controls the centrifuge rotor to rotate slowly by giving preset energy during the positioning process, and simultaneously detects the real-time angle of the rotor to form a closed-loop control, first realizing the fuzzy rough positioning of the centrifuge rotor, and then extending the guide rod of the positioning mechanism to accurately guide and fix the centrifuge rotor, thereby realizing the precise positioning of the centrifuge rotor. The control method of the present invention can realize the positioning of the centrifuge rotor reliably and accurately at a relatively low cost, and can completely replace the general positioning method of customizing high-cost servo motors in the prior art, which can save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0024] Figure 1 A control flow diagram of a centrifuge positioning control method according to an embodiment of the present invention;

[0025] Figure 2 It is a schematic structural diagram of a centrifuge rotor involved in an embodiment of the present invention (101, 102, 103 and 104 are different positioning positions of the centrifuge rotor respectively).

[0026] In the figure: DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention. In addition, those skilled in the art can make corresponding combinations of the features in the embodiments and in different embodiments in this document based on the description of this document.

[0028] The embodiments of the present invention are as follows, referring to Figure 1 , a centrifuge positioning control method, comprising the following steps:

[0029] S1, determining the positioning position and positioning target angle of the centrifuge rotor;

[0030] S2, detecting the real-time angle of the centrifuge rotor;

[0031] S3, calculate the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and determine whether it is greater than a first preset value. If it is less than or equal to the first preset value, execute step S6; if it is greater than the first preset value, execute step S4.

[0032] S4, starting the centrifuge to drive the rotor to rotate slowly according to the preset energy value and continuously detecting the real-time angle of the centrifuge rotor;

[0033] S5, calculating the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and judging whether it is greater than a second preset value, if it is less than or equal to the second preset value, controlling the centrifuge rotor to hover quickly and then executing step S3; if it is greater than the second preset value, executing step S4;

[0034] S6, controlling the centrifuge output energy to 0, and the centrifuge rotor is in a free stop state;

[0035] S7, controlling the guide rod of the positioning mechanism to extend to position the centrifuge rotor;

[0036] S8, calculate the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and determine whether it is greater than a third preset value. If it is less than or equal to the third preset value, the positioning is completed; if it is greater than the third preset value, execute step S2.

[0037] The present invention is used for positioning a high-speed centrifuge after completing a centrifugal operation. In a specific application, a presettable energy is given to control the centrifuge rotor to rotate slowly, and the real-time angle of the rotor is detected to form a closed-loop control. The fuzzy rough positioning of the centrifuge rotor is first realized, and then the guide rod of the positioning mechanism is extended to accurately guide and fix the centrifuge rotor, thereby realizing the precise positioning of the centrifuge rotor.

[0038] Based on the above embodiment, in another embodiment of the present invention, Figure 1 The positioning mechanism is provided with a first position sensor for detecting the extended position of the guide rod. In the step S7, the driving member of the positioning mechanism is first started to drive the guide rod to extend. When the signal of the position sensor is detected, the positioning driving member is controlled to stop moving.

[0039] Based on the above embodiment, in another embodiment of the present invention, Figure 1 The positioning mechanism is provided with a second position sensor for detecting the return position of the guide rod. The step S2 also includes the step of detecting whether the guide rod has returned: detecting the signal of the second position sensor. If the signal of the second position sensor is not detected, the driving member of the positioning mechanism is controlled to move to drive the guide rod to retract until the signal of the second position sensor is detected, and then the positioning driving member is controlled to stop moving.

[0040] Based on the above embodiment, in another embodiment of the present invention, the step of locating the zero angle position of the centrifuge rotor is further included before step S1, and the angle between the located position of the centrifuge rotor and the zero angle position is the positioning target angle.

[0041] Based on the above embodiment, in another embodiment of the present invention, Figure 1 After step S6 is executed, step S7 is executed after a predetermined time delay; in a specific embodiment, the predetermined time is 1s.

[0042] Based on the above embodiment, in another embodiment of the present invention, Figure 1 The positioning end of the guide rod is in the shape of a semi-spherical head, and a conical guide hole is provided at the bottom of the hanging cup at the positioning position of the centrifuge rotor. In the step S7, the guide rod is controlled to extend upward. During the extension process, the positioning end of the guide rod cooperates with the conical guide hole at the bottom of the hanging cup at the positioning position of the centrifuge rotor and is inserted into the conical guide hole.

[0043] On the basis of the above embodiment, in another embodiment of the present invention, the positioning mechanism is provided with a guide sleeve, the guide rod passes through the guide sleeve, and the guide rod is guided by the guide sleeve when moving vertically.

[0044] A specific embodiment, such as Figure 1 After the centrifugation operation is completed, first set the zero angle position of the centrifuge rotor, such as Figure 2 The position corresponding to the middle rotor 101, and then start the positioning function, the execution process is as follows:

[0045] S1, determine the positioning position and positioning target angle of the centrifuge rotor: set the positioning position of the centrifuge rotor through the host computer, Figure 2 The position corresponding to the middle rotor 103, at this time the positioning target angle is 180°, start positioning, and set the positioning command to 1;

[0046] S2, the controller continuously detects the real-time angle of the centrifuge rotor (after centrifugation is completed, the rotor assembly is stationary, such as the angle detection feedback value is 500, i.e. 50°); and determines whether the guide rod is retracted into place, and detects the electrical signal of the second position sensor of the guide rod of the positioning mechanism being retracted into place. If not detected, the guide rod is controlled to be retracted until the electrical signal of the second position sensor is detected, that is, the guide rod movement is stopped;

[0047] S3, calculate in real time the absolute value of the difference between the real-time angle (0-360°) of the centrifuge rotor and the positioning target angle of 180° (an example value is 1800-500=1300, i.e. 130°), and determine whether it is greater than a preset value 1 (an example value is 50, indicating 5°); if it is less than or equal to 50, execute step S6; if it is greater than the preset value 1 (an example value is 50, indicating 5°), enter step S4;

[0048] S4, starting the centrifuge drive rotor to rotate slowly according to a preset energy value 1 (an example value is 7500, which represents the product of a starting speed of 500 and a duty cycle of 15). During the rotation of the centrifuge rotor assembly 1, the absolute value of the difference between its real-time angle and the positioning target angle of 180° (the above example is 1300) is continuously reduced;

[0049] S5, when the absolute value of the angle difference is less than or equal to a preset value 2 (an example value is 75, indicating 7.5°), the centrifuge rotor is controlled to hover quickly, and after it stops completely, the process returns to step S3; if the absolute value of the angle difference is greater than the preset value 2, step S4 is executed;

[0050] S6. Control the centrifugal motor output energy to 0, and the centrifuge rotor is in a free stop state (freely rotating);

[0051] S7, controlling the guide rod of the positioning mechanism to extend, and when an electrical signal of the first position sensor is detected indicating that the guide rod has extended into position, the guide rod stops moving;

[0052] S8, determine the absolute value of the difference between the real-time angle (0-360°) of the rotor assembly 1 and the positioning target angle of 180° (the instance value is 1800-1799=1, i.e. 0.1°). If it is less than or equal to the preset value 3 (the instance value is 10, indicating 1°), it indicates that the positioning is successful and the positioning instruction is cleared; if it is greater than the preset value 3 (the instance value is 10, indicating 1°), it indicates that the positioning has failed, and return to execute step S2.

[0053] The specific embodiment is positioned successfully, and the positioning accuracy is 0.1°. Among them, after executing step S6, the centrifuge rotor assembly 1 is in a free stop state and can rotate freely. After executing step S6, the drive motor (DC motor) of the guide rod is controlled to drive the guide rod to extend through the vertical guide of the guide sleeve. During the extension process, the semi-circular spherical head of the positioning end of the guide rod cooperates with the 90° conical guide hole at the bottom of the hanging cup at the upper rotor positioning position. The guide rod automatically finds the upper hanging cup and inserts into the bottom of the hanging cup. When the first position sensor signal is connected when it is extended into place, the drive member immediately stops the action, and the guide rod inserted into the bottom of the hanging cup is stationary, and its center line coincides with the center line of the hanging cup, thereby realizing the accurate and reliable positioning of the rotor hanging cup at the 103 positioning position.

[0054] The present invention controls the centrifuge rotor to rotate slowly by giving preset energy, and detects the real-time angle of the rotor to form a closed-loop control at the same time. By setting the preset value of the angle difference under different positioning conditions, when the rotor is at any angle (0-360°), the coarse positioning (positioning error within ±5°) of the centrifuge rotor to the positioning target angle (0°, 90°, 180°, 270°) can be reliably achieved first, and then the guide rod of the positioning mechanism is extended to accurately guide and fix the centrifuge rotor, thereby achieving precise positioning of the centrifuge rotor. The control method can reliably and accurately achieve the positioning of the centrifuge rotor at a relatively low cost. After multiple repeated positioning tests in actual application, the positioning accuracy can reach ±0.2°, and the positioning accuracy is extremely high, which can completely replace the existing general positioning method of customizing high-cost servo motors.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A centrifuge positioning control method, characterized in that: The steps include: S1, determining the positioning position and positioning target angle of the centrifuge rotor; S2, detecting the real-time angle of the centrifuge rotor; S3, calculate the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and determine whether it is greater than a first preset value. If it is less than or equal to the first preset value, execute step S6; if it is greater than the first preset value, execute step S4. S4, starting the centrifuge to drive the rotor to rotate slowly according to the preset energy value and continuously detecting the real-time angle of the centrifuge rotor; S5, calculating the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and judging whether it is greater than a second preset value, if it is less than or equal to the second preset value, controlling the centrifuge rotor to hover quickly and then executing step S3; if it is greater than the second preset value, executing step S4; S6, controlling the centrifuge output energy to 0, and the centrifuge rotor is in a free stop state; S7, controlling the guide rod of the positioning mechanism to extend to position the centrifuge rotor; S8, calculate the absolute value of the difference between the detected real-time angle of the centrifuge rotor and the positioning target angle, and determine whether it is greater than a third preset value. If it is less than or equal to the third preset value, the positioning is completed; if it is greater than the third preset value, execute step S2.

2. The centrifuge positioning control method according to claim 1, characterized in that: The positioning mechanism is provided with a first position sensor for detecting the extended position of the guide rod. In step S7, the driving member of the positioning mechanism is first started to drive the guide rod to extend. When the signal of the position sensor is detected, the positioning driving member is controlled to stop moving.

3. The centrifuge positioning control method according to claim 2, characterized in that: The positioning mechanism is provided with a second position sensor for detecting the return position of the guide rod. The step S2 also includes the step of detecting whether the guide rod has returned: detecting the signal of the second position sensor. If the signal of the second position sensor is not detected, the driving member of the positioning mechanism is controlled to move to drive the guide rod to retract until the signal of the second position sensor is detected, and then the positioning driving member is controlled to stop moving.

4. The centrifuge positioning control method according to any one of claims 1 to 3, characterized in that: The step S1 also includes the step of locating the zero angle position of the centrifuge rotor, and the angle between the located position of the centrifuge rotor and the zero angle position is the positioning target angle.

5. The centrifuge positioning control method according to claim 4, characterized in that: After the step S6 is executed, the step S7 is executed after a predetermined delay.

6. The centrifuge positioning control method according to claim 5, characterized in that: The positioning end of the guide rod is in the shape of a semi-spherical head, and a conical guide hole is provided at the bottom of the hanging cup at the positioning position of the centrifuge rotor. In the step S7, the guide rod is controlled to extend upward, and during the extension process, the positioning end of the guide rod cooperates with and is inserted into the conical guide hole at the bottom of the hanging cup at the positioning position of the centrifuge rotor.

7. The centrifuge positioning control method according to claim 3, characterized in that: The positioning mechanism is provided with a guide sleeve, the guide rod passes through the guide sleeve, and the guide rod is guided by the guide sleeve when moving vertically.

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