CN112295625A

CN112295625A - Fine pipetting mechanical arm and operating system thereof

Info

Publication number: CN112295625A
Application number: CN201910691557.7A
Authority: CN
Inventors: 张欣烨
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-07-29
Filing date: 2019-07-29
Publication date: 2021-02-02

Abstract

The invention provides a refined pipetting mechanical arm and an operating system thereof, wherein the mechanical arm comprises an experiment platform, a reagent bottle, a bracket, a parallel motion platform, a pipetting pump, a pipettor, a liquid level sensor, a PLC and an industrial personal computer, the mechanical arm adopts a servo control system of PC + PLC, the parallel motion platform, the pipetting pump, the pipettor and the liquid level sensor are all controlled by the PLC, and the PLC is communicated with the industrial personal computer through an R232 serial port.

Description

Fine pipetting mechanical arm and operating system thereof

Technical Field

The invention relates to the field of medical instruments, in particular to a refined pipetting mechanical arm and an operating system thereof.

Background

A micropipettor, commonly known as a pipette, is a device for quantitatively transferring liquid, and is widely used in the fields of basic research of life science, drug research and development, cell and animal level toxicology evaluation in the field of public health, high-throughput detection in disease and prevention centers, pharmaceutical analytics, pharmacogenomics, and the like. Micropipettes are developed today, and not only are the samples loaded more accurately, but also the varieties are diverse, such as microdispensers, multichannel microsamplers, and the like.

The micropipette is one of common instruments in a laboratory, has indispensable effect in many precision measurement experiments, but the prior pipette has the following defects, for example, the pipette commonly used in the laboratory adopts a manual operation mode, and the repeatability of related experiments is generally higher, so the operation process is relatively complicated, and a lot of inconvenience is brought to the experiment operation.

Most guns in laboratory all adopt air cushion (piston stroke) application of sample now, this when the application of sample, because rifle head exit is tiny, when making the liquid be beaten out, there is very big impact force, this when carrying out the application of sample in some cells and molecular experiment, there is very big damage to cell or molecule in test tube or the culture dish, so in the experiment of some needs gentle application of sample, experiment operating personnel's hand dynamics need be controlled well, in case the error appears, also can cause very big influence to follow-up experiment, be unfavorable for the experiment and go on, consequently, need a liquid-transfering gun that can soft stable application of sample. In some experiments, a plurality of continuous equal-quantity liquid drops are sometimes needed, and the conventional liquid transfer gun cannot ensure the uniformity of the continuous sample adding quantity in the process of drip sample adding due to the uncontrollable hand strength.

Disclosure of Invention

In order to solve the technical problems, the invention provides the fine pipetting mechanical arm and the operating system thereof.

The invention is realized by the following technical scheme:

become liquid arm and operating system that moves liquid more meticulously, full-automatic trace moves liquid platform includes: the device comprises an experiment platform, reagent bottles, a support, a parallel motion platform, a liquid transfer pump, a liquid transfer device, a liquid level sensor, a PLC and an industrial personal computer.

Further, set up A district and B district on the experiment platform, all be provided with positioning slot a plurality of, wherein the A district is used for placing the reagent bottle that contains the liquid of treating the operation, and the B district is used for placing empty reagent bottle or contains the reagent bottle of treating the mixed liquid, the support is fixed on the experiment platform, is located positioning slot directly over, parallel motion platform fixes on the support, the pipettor is fixed on parallel motion platform's movable platform, move the liquid pump and fix on the support, be connected with the pipettor pipeline for drive pipettor work, level sensor is located the front end of pipettor for carry out the precision measurement to the liquid level of the liquid reagent in the reagent bottle, PLC, the industrial computer is located the experiment platform.

Furthermore, the parallel motion comprises a static platform, a dynamic platform, three single open chains I, II and III and three servo motors, and the parallel motion platform further comprises a specific topological structure.

Further, the topology of the parallel motion platform is 3-RRC, the structure of single split chain I (R11 | R12 | C13) is equivalent to (R11 | R12 | R131| P132); the structural arrangement of the single-split chain II is the same as that of I, and the moving chain structure (R21 | R22 | C23) is equivalent to (R21 | R22 | R231| P232); the structural arrangement of the single-split chain III is the same as that of I, and the moving chain structure (R31 | R32 | C33) is equivalent to (R31 | R32 | R331| P332).

Furthermore, the axes of the revolute pairs R11, R21 and R31 are coplanar and are positioned on the static platform, the two axes of the R11 and R21 pairs are parallel to each other, and the axis of the R31 pair is perpendicularly intersected with the axes.

Further, the parallel motion platform comprises cylindrical pairs C12, C22 and C32, wherein the axes of the cylindrical pairs C12, C22 and C32 are coplanar and are positioned on the moving platform, the parallel motion platform has three translational degrees of freedom and is respectively in translational motion along an X axis, a Y axis and a Z axis, and the driving pairs of the parallel motion platform are revolute pairs R11, R21 and R31 and are respectively driven by corresponding servo motors M1, M2 and M3.

The invention has the beneficial effects that:

the invention provides a refined pipetting mechanical arm and an operating system thereof, and the accuracy and consistency of position movement are better solved by adopting the position control of an alternating current servo system controlled by a PLC and an industrial personal computer; the parallel motion platform is adopted to take the revolute pair as the driving pair to replace the traditional three-axis motion platform, so that the problems of position consistency and starting origin reset caused by abrasion in the long-term moving process of the sliding block are solved, the working efficiency of the liquid transfer platform is improved, the position control resolution is high, and the automatic coordination performance is good. The liquid-transfering platform does not fix the position location on a certain numerical value, but changes with the position of the target liquid in real time, the performance of the control system is always in an optimal state, the smoothness of liquid-transfering of the system is kept by using a scheme of a closed-loop PID control system, the anti-interference capability is enhanced, the influence of the friction and the liquid quality of each part on the parallel motion platform is overcome, the service life of the instrument is prolonged, and possible faults are eliminated. According to the invention, under the regulation and control of the PLC intelligent control system, all links are mutually matched, the automation degree is high, the operation is simple, the micro-pipetting efficiency is high, and the labor intensity of personnel is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a fine pipetting robot arm and an operating system thereof provided in this embodiment;

FIG. 2 is a schematic diagram of a parallel motion platform provided in this embodiment;

FIG. 3 is a schematic diagram of the PLC overall framework of the fully automatic micropipette platform provided in the present embodiment;

FIG. 4 is a schematic diagram of the PLC workflow of the fully automatic micropipette platform provided in this embodiment.

Wherein: 1-experiment platform, 2-reagent bottle, 3-bracket, 4-parallel motion platform, 5-liquid transferring pump, 6-liquid transferring pump, 7-liquid level sensor, 8-PLC, 9-industrial personal computer, 401-static platform, 402-dynamic platform, I-single open chain I, II-single open chain II, III-single open chain III.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

Example 1:

as shown in fig. 1, the full-automatic micropipette platform includes: experiment platform 1, reagent bottle 2, support 3, parallel motion platform 4, move liquid pump 5, pipettor 6, level sensor 7, PLC 8, industrial computer 9. The experiment platform is provided with an area A and an area B, the area A and the area B are provided with a plurality of positioning clamping grooves, the area A is used for placing reagent bottles containing liquid to be operated, the area B is used for placing empty reagent bottles or reagent bottles containing liquid to be mixed, the support is fixed on the experiment platform and located right above the positioning clamping grooves, the parallel motion platform is fixed on the support, the pipettor is fixed on a moving platform of the parallel motion platform, the pipetting pump is fixed on the support and connected with a pipettor pipeline for driving the pipettor to work, the liquid level sensor is located at the front end of the pipettor and used for accurately measuring the liquid level of the liquid reagent in the reagent bottles, and the PLC and the industrial personal computer are located on the experiment platform and jointly complete intelligent control over the full-automatic micro pipetting platform.

Further, the parallel moving platform is shown in fig. 2, and comprises a static platform 401, a moving platform 402, three single open chains I, ii, iii and three servomotors, the parallel moving platform further comprises a specific topology, the topology of the parallel moving platform is 3-RRC, the structure of the single open chain I (R11 | R12 | C13) is equivalent to (R11 | R12 | R131| P132); the structural arrangement of the single-split chain II is the same as that of I, and the moving chain structure (R21 | R22 | C23) is equivalent to (R21 | R22 | R231| P232); the structural arrangement of the single-split chain III is the same as that of the single-split chain I, and the moving chain structure (R31 | R32 | C33) is equivalent to (R31 | R32 | R331| P332), wherein the axes of the rotating pairs R11, R21 and R31 are coplanar and are all positioned on the static platform, the two axes of the R11 and R21 pairs are parallel to each other, and the axis of the R31 pair is vertically intersected with the stationary platform; the axes of the cylindrical pairs C12, C22 and C32 are coplanar and are all positioned on the movable platform, the parallel movable platform has three translational degrees of freedom, namely translational motions along an X axis, a Y axis and a Z axis, and the driving pairs of the parallel movable platform are revolute pairs R11, R21 and R31 which are respectively driven by corresponding servo motors M1, M2 and M3.

Example 2:

the overall architecture of the refined liquid-transferring mechanical arm and the operation system thereof is shown in fig. 3, and the PLC is respectively electrically connected with an industrial personal computer, a servo motor M1, a servo motor M2, a servo motor M3, a liquid-transferring pump, a liquid-transferring machine and a liquid level sensor. The PLC is electrically connected with an industrial personal computer and is used for setting parameters such as liquid amount, extraction times, the number of reagent bottles to be operated and the like of single extraction; the PLC is electrically connected with the liquid transfer pump and the liquid transfer device and is used for pumping or spitting out a reagent; the PLC is electrically connected with the servo motors M1, M2 and M3 and is used for driving the corresponding revolute pairs R11, R21 and R31 to operate in parallel, and the operating speed, direction and displacement of the three servo motors are controlled according to the frequency, direction and number of pulses sent by the PLC, so that the displacement and speed of the parallel motion platform are controlled; the PLC is electrically connected with the liquid level sensor and used for feeding back the actual position of the pipettor from the liquid level to form closed-loop control of the parallel motion platform.

Example 3:

become more meticulous and move liquid arm and operating system thereof adopts PC + PLC's servo control system, parallelly connected motion platform, move the liquid pump, pipettor, level sensor all are controlled by the PLC controller, and PLC carries out the communication through R232 serial ports and industrial computer. The work flow of the platform is shown in fig. 4:

1) after the equipment is powered on, a control system is initialized, and a parallel motion platform, a liquid transfer device, a liquid transfer pump and a liquid level sensor are set;

2) after a liquid reagent to be operated is placed in a special reagent bottle of a platform, the liquid reagent is placed in a positioning clamping groove of an experiment platform, the positions of the reagent bottles are placed according to the functional region of the platform in a classified mode, and the number of the placed reagent bottles is determined according to actual requirements;

3) selecting parameters such as operation types, quantity, single extraction amount and the like to be finished on an industrial personal computer, and automatically calculating action parameters of a servo motor, a liquid transfer pump and a liquid transfer device by software;

4) clicking a starting button on an industrial personal computer, starting a parallel motion platform, quickly translating a pipettor to a position right above a first reagent bottle in a designated area A, feeding back the pipettor to the industrial personal computer after a liquid level sensor acquires a distance L from the liquid level of liquid to be operated in the reagent bottle, setting a numerical value of liquid extracted by the pipettor each time as a, and driving the pipettor to vertically move downwards to a position of L + a +0.1mm by the parallel motion platform to stop;

5) the industrial personal computer starts the liquid transfer pump and the liquid transfer device to begin to extract liquid with set numerical values, after the liquid is extracted, the parallel platform drives the liquid transfer device to vertically move upwards to leave the reagent bottle, and then the liquid transfer device is quickly translated to the position right above the first reagent bottle in the area B, so that the needle head of the liquid transfer device and the top surface of the reagent bottle are at the same height;

6) the industrial personal computer starts the liquid transfer pump and the liquid transfer machine again, and the trace liquid in the liquid transfer machine is spitted into the reagent bottle to finish the operation of liquid transfer or mixing;

7) and (4) setting the liquid transfer platform according to a program, repeating the steps 4-6, and resetting after all specified operations are completed.

Example 4:

as shown in fig. 2, the number of parallel mechanism-sharing kinematic pairs m of the parallel motion platform is 9, the number of members n is 9, and the degree of freedom (DOF) formula is used as a basis

Determining the degree of freedom (DOF) of the mechanism to be F ═ 3, and the three degrees of freedom are translation along an X axis, a Y axis and a Z axis respectively; if the degree of freedom F' of the obtained new mechanism is 0, the F preselected kinematic pairs may be simultaneously the drive pairs. Since the degree of freedom of the mechanism is 3, the revolute pairs R11, R21 and R31 of the pre-selected 3 branches are driving pairs, and the revolute pairs, R21 and R31 are rigidized to obtain the degree of freedom F' of the mechanism after the rigidization, which is 0, and the driving pair existence criterion is met.

Example 5

A fine pipetting mechanical arm and an operating system thereof can meet the pipetting quantity of 5-50 microlitres per time, and the performance test method of the pipetting platform comprises the following steps: sequentially transferring the liquid with the specified liquid amount in 10 reagent bottles containing the liquid to be operated in the area A to 10 empty reagent bottles at corresponding positions in the area B, extracting each reagent bottle for 10 times, wherein the test liquid is double distilled water and the density is 1g/cm³The single pipetting volume was 10. mu.l. After the full-automatic micropipette platform finishes all operations, all reagent bottles in the area B are placed on a precision electronic balance for weighing, and after the mass of the empty reagent bottles is planed, the obtained experimental results are shown in table 1.

TABLE 1 pipetting performance test results of full-automatic micropipetting platform

The total time for completing the test method by adopting the full-automatic micropipette platform provided by the invention is 5 min. According to experimental results, the full-automatic micro liquid transfer platform is accurate in liquid transfer amount, the maximum liquid transfer error is 1%, the total liquid transfer error is 5% o, technical performance indexes all meet preset requirements, the automation degree is high, the speed is high, the operation is convenient, the efficiency is high, the human-computer interaction environment is friendly, and the full-automatic micro liquid transfer platform is suitable for various industrial research scenes in the fields of medical treatment, research and development and the like.

The full-automatic micropipette platform adopts an alternating current servo system controlled by a PLC and an industrial control machine to control the position, so that the accuracy and consistency of position movement are better solved; the parallel motion platform is adopted to take the revolute pair as the driving pair to replace the traditional three-axis motion platform, so that the problems of position consistency and starting origin reset caused by abrasion in the long-term moving process of the sliding block are solved, the working efficiency of the liquid transfer platform is improved, the position control resolution is high, and the automatic coordination performance is good; the liquid-transfering platform does not fix the position location on a certain numerical value, but changes with the position of the target liquid in real time, the performance of the control system is always in an optimal state, the smoothness of liquid-transfering of the system is kept by using a scheme of a closed-loop PID control system, the anti-interference capability is enhanced, the influence of the friction and the liquid quality of each part on the parallel motion platform is overcome, the service life of the instrument is prolonged, and possible faults are eliminated.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. Become more meticulous and move liquid arm, its characterized in that, the arm includes experiment platform, reagent bottle, and support, parallel motion platform moves the liquid pump, pipettor, level sensor, PLC, industrial computer, PLC respectively with the industrial computer, servo motor M1, servo motor M2, servo motor M3 moves the liquid pump, pipettor, the level sensor electricity is connected, the arm adopts PC + PLC's servo control system, parallel motion platform, move the liquid pump, pipettor, level sensor all are controlled by the PLC controller, and PLC carries out the communication through R232 serial ports and industrial computer.

2. The mechanical arm according to claim 1, wherein the PLC is electrically connected with an industrial personal computer and used for setting parameters such as liquid amount, extraction times, the number of reagent bottles to be operated and the like of single extraction; and the PLC is electrically connected with the liquid transfer pump and the liquid transfer device and is used for pumping or spitting out the reagent.

3. The mechanical arm of claim 1, wherein the PLC is electrically connected with a servo motor M1, a servo motor M2 and a servo motor M3 and is used for driving corresponding revolute pairs R11, R21 and R31 to operate in parallel, and the speed, the direction and the displacement of the operation of the three servo motors are controlled according to the frequency, the direction and the number of pulses sent by the PLC, so that the displacement and the speed of the parallel motion platform are controlled.

4. The mechanical arm according to claim 1, wherein the PLC is electrically connected with a liquid level sensor and used for feeding back the actual position of the pipettor from the liquid level to form closed-loop control of the parallel motion platform.

5. The robotic arm of claim 1, wherein the robotic arm handling system comprises:

step one, after equipment is powered on, a control system is initialized, and a parallel motion platform, a liquid transfer device, a liquid transfer pump and a liquid level sensor are set; secondly, placing liquid reagents to be operated into special reagent bottles of the platform and then into positioning clamping grooves of the experiment platform, wherein the positions of the reagent bottles are placed according to the functional regions of the platform in a classified manner, and the number of the placed reagent bottles is determined according to actual requirements; selecting parameters such as operation types, quantity, single extraction quantity and the like to be finished on an industrial personal computer, and automatically calculating action parameters of a servo motor, a liquid transfer pump and a liquid transfer device by software; clicking a starting button on an industrial personal computer, starting a parallel motion platform, quickly translating a pipettor to a position right above a first reagent bottle in a designated area A, feeding back the pipettor to the industrial personal computer after a liquid level sensor collects a distance L from the liquid level of liquid to be operated in the reagent bottle, setting a numerical value of liquid extracted by the pipettor each time as a, and driving the pipettor to vertically move downwards to a position L + a +0.1mm by the parallel motion platform to stop; the industrial personal computer starts the liquid transfer pump and the liquid transfer device to begin to extract liquid with set numerical values, after the liquid is extracted, the parallel platform drives the liquid transfer device to vertically move upwards to leave the reagent bottle, and then the liquid transfer device is quickly translated to the position right above the first reagent bottle in the area B, so that the needle head of the liquid transfer device and the top surface of the reagent bottle are at the same height; the industrial personal computer starts the liquid transfer pump and the liquid transfer machine again, and micro liquid in the liquid transfer machine is spit into the reagent bottle to finish the operation of liquid transfer or mixing; and step seven, setting the liquid transfer platform according to a program, repeating the steps 4-6, and resetting after all specified operations are completed.