A high-precision automatic liquid transfer device and liquid transfer method for automated laboratories

Abstract

The present invention belongs to the technical field of automated laboratories, and specifically relates to a high-precision automatic pipetting device and a pipetting method for automated laboratories, comprising: a controller, a device housing, a pipetting drive unit, a pipetting motion unit, and a pipetting unit; the pipetting drive unit is fixedly mounted on the device housing and connected to the pipetting motion unit, and drives the pipetting motion unit to move in a vertical direction through high-resolution control of a motor; the pipetting motion unit is connected to the pipetting unit and the pipetting drive unit, respectively; the pipetting unit is disposed in the device housing and connected to the pipetting motion unit, and is driven by the pipetting motion unit to perform reciprocating motion of a plunger to achieve a pipetting operation; the controller is connected to the pipetting drive unit, and is used to receive an actual steady-state airtight cavity pressure P sent by the pipetting unit. a , constructing an intelligent plunger rod stroke setting model, and at the same time, combining the stepper motor high-resolution control method to control and adjust the pipetting drive unit. The piston movement in the present invention has good parallelism and is not prone to failure.

Description

Technical Field

[0001] The invention belongs to the technical field of automated laboratories, in particular to a high-precision automatic liquid transfer device and a liquid transfer method for automated laboratories. Background Art

[0002] In the biological sciences, automated pipetting devices are widely used in molecular biology experiments, plasmid extraction, PCR system development, and media replacement during cell culture. In the chemical sciences, automated pipetting devices are used for precise preparation of chemical reagents, drug synthesis, and sample preparation. In clinical and pharmaceutical research, automated pipetting devices ensure the accuracy and traceability of drug formulations and help researchers rapidly process large numbers of samples.

[0003] High-precision automatic pipetting devices and methods play an important role in laboratories across multiple fields, particularly in liquid handling processes requiring high precision and repeatability. Currently, the main pipetting device in laboratories is a manual pipette, which is manually operated by experimental operators based on their experience. This variability in operation between operators results in poor pipetting consistency. Because manual pipettes lack a pipetting chamber pressure detector, it is difficult for operators to quantitatively consider the impact of the pipetting chamber pressure on pipetting, resulting in low pipetting accuracy. Furthermore, manual pipettes cannot be integrated into automated devices, significantly limiting their use. The high-precision automatic pipetting device and pipetting method provided by the present invention can reduce manual operation, reduce human error during experiments, and improve the accuracy and reliability of experimental data. They can quantitatively describe the impact of the pipetting chamber pressure on pipetting, thereby enabling high-precision liquid movement and distribution, significantly improving experimental efficiency and the consistency of results. With the development of laboratory automation and information technology, the high-precision automatic pipetting device and pipetting method provided by the present invention can provide more efficient and accurate experimental means for scientific research, thereby promoting progress in scientific research and medical diagnosis. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-precision automatic pipetting device and pipetting method for automated laboratories. Based on the basic principle of air replacing liquid, the actual steady-state airtight plunger internal pressure is used for auxiliary judgment according to the desired pipetting volume and the actual atmospheric pressure. Through the intelligent setting model of the plunger rod stroke and the high-precision control of the stepping motor, fast and high-precision pipetting is achieved.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned object is: a high-precision automatic pipetting device for automated laboratories, comprising: a controller, a device housing, a pipetting drive unit, a pipetting motion unit, and a pipetting unit;

[0006] The pipetting drive unit is fixed to the device housing and connected to the pipetting motion unit. It is used to receive the motor subdivision number sent by the controller, perform high-subdivision control of the stepping motor, and drive the pipetting motion unit to move in the vertical direction. At the same time, it receives the position trigger signal in real time. When the position trigger signal is detected, the pipetting drive unit stops working.

[0007] The pipetting motion unit is connected to the pipetting unit and the pipetting drive unit respectively, and is used to be driven by the pipetting drive unit to drive the pipetting unit to move in coordination;

[0008] The pipetting unit is arranged in the housing of the device and is connected to the pipetting motion unit. It is used to drive the pipetting motion unit to perform the reciprocating motion of the plunger to realize the pipetting operation. At the same time, the actual steady-state pressure P in the airtight cavity is a Send to the controller for processing;

[0009] The controller is connected to the pipetting drive unit and is used to receive the actual steady-state airtight cavity pressure P sent by the pipetting unit. a , build an intelligent setting model for the plunger rod stroke, and at the same time, send the motor subdivision number to the pipetting drive unit, and combine the stepper motor high subdivision control method to control and adjust the pipetting drive unit.

[0010] The pipetting drive unit includes: a stepping motor, a photoelectric switch and a photoelectric switch baffle;

[0011] The stepper motor is a through-type stepper motor. The motor body of the stepper motor is fixedly mounted on the device housing. The through-axis of the stepper motor is perpendicular to the top surface of the device housing. One end of the through-axis passes through the motor body and is inserted into a corresponding cavity of the device housing. The other end is fixedly connected to the pipetting motion unit. When the stepper motor receives a command from the controller, it drives the through-axis to move downward and drives the pipetting motion unit to move downward.

[0012] The photoelectric switch baffle is fixed on the pipetting motion unit, and the photoelectric switch baffle is perpendicular to the horizontal plane and parallel to the through axis; the photoelectric switch baffle corresponds to the position of the photoelectric switch provided on the device housing. When the pipetting motion unit moves downward, it drives the photoelectric switch baffle to insert and trigger the photoelectric switch to receive a position trigger signal. The photoelectric switch sends a stop operation instruction and is connected to the stepper motor to control the stepper motor to stop working.

[0013] The pipetting motion unit includes: a lifting plate, a connecting plate, an auxiliary connecting rod, a slider and a parallel track;

[0014] The lifting plate is arranged parallel to the horizontal plane and is connected to the through shaft of the pipetting drive unit; a photoelectric switch baffle is fixed on the lifting plate;

[0015] A fixing plate is provided on the top surface of the device housing below the lifting plate, and a plurality of auxiliary connecting rods are vertically provided on the bottom surface of the lifting plate. The auxiliary connecting rods are slidably arranged in the through holes of the fixing plate and inserted into the cavity provided in the device housing to limit the displacement of the lifting plate;

[0016] The parallel track is vertically arranged on the device housing, and the arrangement position of the parallel track is located on the same side as the connecting plate; a slider is slidably provided on the parallel track, and the slider is fixedly connected to the connecting plate to limit the displacement of the pipetting motion unit;

[0017] The pipetting drive unit moves, driving the lifting plate to descend, and the lifting plate is limited in its downward displacement by the connecting plate and the auxiliary connecting rod. When the lifting plate drives the photoelectric switch baffle to trigger the photoelectric switch, the pipetting drive unit stops moving.

[0018] The pipetting unit comprises: a plunger rod, an airtight plunger, a stable airtight cavity, a connecting tube, a TIP head pipe and a pressure sensor;

[0019] The stable airtight cavity is vertically arranged in the device housing;

[0020] The airtight plunger is arranged in the stable airtight cavity and is adapted to the stable airtight cavity; the outer ring of the airtight plunger is provided with an O-ring to improve the airtightness of the pipetting unit;

[0021] One end of the plunger rod passes through the fixed plate on the device housing and is fixedly connected to the airtight plunger, and the other end is fixedly connected to the lifting plate through a pin shaft, so as to achieve the downward displacement of the lifting plate and push the airtight plunger to compress the stable airtight cavity;

[0022] A pressure sensor is provided on the device housing at the lowest position of the corresponding steady-state airtight cavity to monitor the actual pressure P in the steady-state airtight cavity. a and send it to the controller;

[0023] The TIP connector is provided on the bottom surface of the device housing, and is connected to the bottom of the stable airtight cavity through a connecting pipe;

[0024] The TIP head pipe is provided with a pipe withdrawal ring, and the pipe withdrawal ring is clamped in the device housing;

[0025] A return spring is sleeved on the connecting pipe, and one end of the return spring abuts against the auxiliary connecting rod, and the other end abuts against the pipe withdrawal ring;

[0026] When the plunger rod moves downward to the bottom of the airtight cavity, the lifting plate presses down the auxiliary connecting rod, the auxiliary connecting rod compresses the return spring, the return spring compresses the tube withdrawal ring downward, and the tube withdrawal ring moves downward, thereby removing the TIP head;

[0027] An O-type sealing ring is also sleeved on the TIP head pipe to prevent leakage.

[0028] An automatic pipetting method for a high-precision automatic pipetting device for an automated laboratory, comprising the following steps:

[0029] 1) Place the TIP connector against the TIP connector and press the TIP connector onto the connector to complete the installation.

[0030] 2) When the through-type stepper motor receives the action command from the controller, it drives the through-type shaft to move, which in turn drives the plunger rod to move through the lifting plate, thereby changing the volume and pressure of the steady-state airtight chamber. Through air replacement, the pipetting unit completes the functions of aspirating and discharging liquids.

[0031] 3) When the through-axis moves upward, the controller controls the pipetting drive unit through the intelligent setting model of the plunger rod stroke and the high-resolution control of the stepper motor to complete the TIP head pipetting operation;

[0032] 4) When the through-axis moves downward, the liquid dispensing operation of the TIP pipe of the pipetting unit is completed. When the plunger rod moves downward to the bottom of the airtight cavity, the lifting plate presses down the auxiliary connecting rod, which compresses the return spring. The return spring compresses the tube withdrawal ring downward, and the tube withdrawal ring moves downward, thereby removing the TIP from the TIP pipe.

[0033] 5) Repeat steps 1) to 4) to achieve the distribution of multiple liquids.

[0034] In step 3), the plunger rod stroke intelligent setting model is as follows: a preset value of the plunger rod stroke is obtained based on the actual local atmospheric pressure and the desired pipetting volume; and an auxiliary judgment is made based on the pressure inside the airtight plunger in a steady state to adjust the preset value of the plunger rod stroke;

[0035] The method includes establishing the plunger rod stroke intelligent setting model and completing the motion control of the pipetting drive unit through the controller according to the plunger rod stroke intelligent setting model, including the following steps:

[0036] Assume that the atmospheric pressure is P0, the desired pipetting volume is V, the plunger rod stroke is H, and the corresponding airtight plunger internal pressure is P. P is taken as the ideal steady-state airtight plunger internal pressure.

[0037] For a certain specification of TIP head, with P0 and V as input variables, H as output variable, and P as auxiliary variable, the whale optimization algorithm-least squares support vector machine method is used to establish a preset model of the plunger rod stroke and an ideal steady-state airtight plunger internal pressure prediction model, namely:

[0038] (1) Let X be the matrix composed of the sample data of the input variables P0 and V, and Y and Z be the matrices composed of the sample data of the corresponding output variables H and auxiliary variables P, respectively. Then:

[0039]

[0040] in, is the data of input variable P0, is the data of input variable V, N is the number of samples; let x i =[x 1i ,x 2i ], represents the input of the i-th sample of the plunger rod stroke preset model and the ideal steady-state airtight plunger internal pressure prediction model, y i represents the output of the i-th sample of the plunger rod stroke preset model, z i represents the output of the i-th sample of the ideal steady-state airtight plunger internal pressure prediction model, i = 1, 2, ..., N;

[0041] (2) Using the whale optimization algorithm-least squares support vector machine method to establish a plunger rod stroke preset model;

[0042] The plunger rod stroke preset model is established using the LSSVM method. The input variables of the model are P0 and V, and the output variable is H. The kernel function in the LSSVM method adopts the form of radial basis function, and the width of the radial basis function is set to σ, and the regularization parameter is γ.

[0043] The vector [σ,γ] composed of σ and γ is used as the position of the whale individual. The positions of several whale individuals are randomly generated. For the parameters σ and γ in each whale individual position, a model is established using sample data and the LSSVM method. The parameters σ and γ in the model are optimized using the whale optimization algorithm. The upper and lower limits of the optimized parameter σ are σ and γ, respectively. max and σ min , the upper and lower limits of γ are γ max and γ min , the parameters σ and γ obtained after optimization are substituted into the LSSVM model to obtain the plunger rod stroke preset model;

[0044] (3) Using the whale optimization algorithm-least squares support vector machine method, an ideal steady-state airtight plunger internal pressure prediction model is established;

[0045] (4) Adjust the plunger rod stroke and complete the motion control of the pipetting drive unit through the controller.

[0046] The step (2) is specifically:

[0047] (2-1) Set the current number of iterations t = 1 and the maximum number of iterations Tmax =15;

[0048] (2-2) Randomly generate N A = The positions of 20 initial whale individuals, the position of each whale individual is:

[0049] S k (t)=[σ min +rand1(σ max -σ min ),γ min +rand2(γ max -γ min )] T

[0050] Where k = 1, 2, ..., N A , rand1 and rand2 are both random numbers in the range [0, 1], σ max =2 9 , σ min =2 -9 , γ max =10 4 , γ min =10 -4 ;

[0051] (2-3) Based on the position of each whale individual, the corresponding LSSVM model is established using the sample data, where the kernel function is:

[0052]

[0053] Where σ is the width of the radial basis function, x i =[x 1i ,x 2i ], represents the input of the i-th sample, i=1,2,...,N,S k (t)[1] represents S k the first component of (t);

[0054] (2-4) Then the output of the LSSVM model corresponding to the kth whale individual position is:

[0055]

[0056] Solve α by the following formula i and d, that is:

[0057]

[0058] Among them, 1 N =[1,1,...,1] T ,α=[α1,α2,...,α N] T , α represents the weight parameter vector, Ω represents the matrix composed of kernel functions, Ω i,j =K k (x i ,x j ), i=1,2,...,N, j=1,2,...,N,I N is the N-order unit matrix, γ is the regularization parameter, d represents the bias parameter, S k (t)[2] represents S k The parameters σ and γ in the LSSVM model corresponding to the kth whale individual position are both given by S k The two components of (t) are given;

[0059] (2-5) According to the position of each whale individual, the fitness function is used:

[0060] Calculate the fitness of the corresponding LSSVM model fit k (t), the whale individual position with the maximum fitness is taken as the optimal whale individual position and recorded as S * (t), determine whether t=T max ;

[0061] (2-6) If satisfied, the position S of the optimal whale individual * (t) is output as the final result and substituted into the LSSVM model. The obtained model is the preset model of the plunger rod stroke. If it is not satisfied, let D k (t) = C k (t)S * (t)-S k (t) represents the position vector between the kth whale individual and the random whale individual; Represents the distance vector between the kth whale individual and the optimal whale individual (i.e., the optimal solution); let A k (t) = 2a(t)r 1k (t)-a(t), a(t) is a parameter that decreases linearly from 2 to 0, and the expression is T max Indicates the maximum number of iterations, r 1k (t) is a random number in the range [0,1], C k (t) = 2r 2k (t), r 2k (t) is a random number in the range [0,1]. Generate a random number β(t) in the range [0,1] and determine whether β(t)≤0.5.

[0062] (2-7) If β(t)≤0.5, then determine whether |Ak (t)|<1, if satisfied, then use S k (t+1)=S * (t)-A k (t)D k (t) Update the position of the kth whale individual, if |A k (t)|≥1, then use S k (t+1)=S rand (t)-A k (t)D k (t) Update the position of the kth whale individual, S rand (t) represents the position of a randomly selected individual whale;

[0063] (2-8) If β(t)>0.5, then use Update the position of the kth whale individual; where b is the spiral shape parameter, ranging from [0.6, 0.7]; l represents a random number uniformly distributed within [-1, 1];

[0064] (2-9) Let t = t + 1, and repeat steps (2-3) to (2-8).

[0065] The step (3) is specifically:

[0066] (3-1) The input variables of the model are P0 and V, and the output variable is P. The parameters are modified in the process of establishing the plunger rod stroke preset model, namely:

[0067] Change the maximum number of iterations in step (2-1) to T max =20;

[0068] Modify the random generation in step (2-2) to N A = the positions of 30 initial whale individuals, the upper and lower limits of the parameter to be optimized σ are modified to σ max =2 10 and σ min =2 -10 , the upper and lower limits of γ are modified to γ max =10 5 and γ min =10 -3 ,

[0069] Then the equation that needs to be solved for the LSSVM model coefficient becomes:

[0070]

[0071] Modify the value range of parameter b in step (2-8) to [0.3, 0.5];

[0072] (3-2) Based on the specific method of the plunger rod stroke preset model and the parameters modified in the corresponding modeling process, an ideal steady-state airtight plunger internal pressure prediction model is obtained;

[0073] The step (4) is specifically:

[0074] After adjusting the plunger rod stroke according to the preset value of the plunger rod stroke, the steady-state airtight plunger internal pressure P a Perform auxiliary judgment and calculate the actual steady-state airtight plunger internal pressure P a The difference ΔP between the predicted value P of the ideal airtight plunger internal pressure and the plunger rod stroke is used to adjust the plunger rod stroke in combination with the plunger rod stroke adjustment rule table.

[0075] The high-resolution precision control of the stepper motor is specifically as follows:

[0076] The controller sends the motor subdivision number to the pipetting drive unit, wherein the subdivision number is an integer between 4 and 64;

[0077] Under the control of the subdivision number and timing state, two-phase linearly changing currents with a difference of π / 2 are passed through the windings of the two-phase stepper motor, thereby realizing subdivision control.

[0078] The present invention has the following beneficial effects and advantages:

[0079] 1. The automated high-precision pipetting device provided by the present invention can be integrated into an automated workstation.

[0080] 2. The piston of the present invention has good parallelism in movement and is less likely to malfunction.

[0081] 3. The process of installing and removing the TIP head of the present invention does not cause extrusion deformation to the TIP head, and the internal and external shapes and sealing surfaces of the TIP head are maintained to the greatest extent, thereby extending the service life and ensuring the accuracy and consistency of the instrument during long-term use.

[0082] 4. This invention uses an intelligent plunger rod stroke setting model and a through-axis stepper motor with high-precision control to ensure liquid absorption and dispensing accuracy. It also uses an airtight plunger cavity, an airtight plunger, and a double-layer O-ring to ensure the airtightness of the maximum 10ml liquid dosage device. A separate TIP head is used for each liquid, which can completely solve the problems of cross-contamination of experimental drugs and device cleaning.

[0083] 5. The through-axis stepper motor in the present invention is used for both TIP head removal and liquid transfer, the motor has high efficiency and the cost of the entire device is lower.

[0084] 6. The present invention adopts the method of installing a photoelectric sensor at the back of the cavity to realize the automatic origin retrieval function, ensuring that the through-axis stepper motor starts to move from the same position every time.

[0085] 7. The present invention establishes an intelligent setting model for the plunger rod stroke for commonly used TIP heads of different specifications, which can achieve the function of fast and high-precision pipetting.

[0086] 8. When establishing the intelligent setting model of the plunger rod stroke, the present invention adopts the whale optimization algorithm (WOA) to optimize the parameters of the plunger rod stroke preset model and the ideal steady-state airtight plunger internal pressure prediction model. The WOA algorithm has the advantages of simple mechanism, few parameters and strong optimization ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 This is an overall structural diagram of the high-precision pipetting device of the present invention;

[0088] Figure 2 is a cross-sectional view of the high-precision liquid transfer device of the present invention;

[0089] Figure 3 The figure is a workflow diagram of the high-precision pipetting device and method of the present invention. DETAILED DESCRIPTION

[0090] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0091] like Figures 1-2 , which are an overall structural diagram and a cross-sectional diagram of a high-precision liquid transfer device according to the present invention, a high-precision automatic liquid transfer device for an automated laboratory according to the present invention comprises: a controller, a device housing, a liquid transfer drive unit, a liquid transfer motion unit, and a liquid transfer unit;

[0092] The pipetting drive unit is fixed to the device housing and connected to the pipetting motion unit. It is used to receive the motor subdivision number sent by the controller, perform high-subdivision control of the stepping motor, and drive the pipetting motion unit to move in the vertical direction. At the same time, it receives the position trigger signal in real time. When the position trigger signal is detected, the pipetting drive unit stops working.

[0093] The pipetting motion unit is connected to the pipetting unit and the pipetting drive unit respectively, and is used to be driven by the pipetting drive unit to drive the pipetting unit to move in coordination;

[0094] The pipetting unit is arranged in the housing of the device and is connected to the pipetting motion unit. It is used to drive the pipetting motion unit to perform the reciprocating motion of the plunger to realize the pipetting operation. At the same time, the actual steady-state pressure P in the airtight cavity is a Send to the controller for processing;

[0095] The controller is connected to the pipetting drive unit and is used to receive the actual steady-state airtight cavity pressure P sent by the pipetting unit. a, build an intelligent setting model for the plunger rod stroke, and at the same time, send the motor subdivision number to the pipetting drive unit, and combine the stepper motor high subdivision control method to control and adjust the pipetting drive unit.

[0096] 1. Pipette drive unit

[0097] A pipetting drive unit, comprising: a stepping motor, a photoelectric switch, and a photoelectric switch baffle;

[0098] The stepper motor is a through-type stepper motor. The motor body of the stepper motor is fixedly mounted on the device housing. The through-axis of the stepper motor is perpendicular to the top surface of the device housing. One end of the through-axis passes through the motor body and is inserted into a corresponding cavity of the device housing. The other end is fixedly connected to the pipetting motion unit. When the stepper motor receives a command from the controller, it drives the through-axis to move downward and drives the pipetting motion unit to move downward.

[0099] The photoelectric switch baffle is fixed on the pipetting motion unit, and the photoelectric switch baffle is perpendicular to the horizontal plane and parallel to the through axis; the photoelectric switch baffle corresponds to the position of the photoelectric switch provided on the device housing. When the pipetting motion unit moves downward, it drives the photoelectric switch baffle to insert and trigger the photoelectric switch to receive a position trigger signal. The photoelectric switch sends a stop operation instruction and is connected to the stepper motor to control the stepper motor to stop working.

[0100] 2. Pipetting motion unit

[0101] A pipetting motion unit, comprising: a lifting plate, a connecting plate, an auxiliary connecting rod, a slider and a parallel track;

[0102] The lifting plate is arranged parallel to the horizontal plane and is connected to the through shaft of the pipetting drive unit; a photoelectric switch baffle is fixed on the lifting plate;

[0103] A fixing plate is provided on the top surface of the device housing below the lifting plate, and a plurality of auxiliary connecting rods are vertically provided on the bottom surface of the lifting plate. The auxiliary connecting rods are slidably arranged in the through holes of the fixing plate and inserted into the cavity provided in the device housing to limit the displacement of the lifting plate;

[0104] The parallel track is vertically arranged on the device housing, and the arrangement position of the parallel track is located on the same side as the connecting plate; a slider is slidably provided on the parallel track, and the slider is fixedly connected to the connecting plate to limit the displacement of the pipetting motion unit;

[0105] The pipetting drive unit moves, driving the lifting plate to descend, and the lifting plate is limited in its downward displacement by the connecting plate and the auxiliary connecting rod. When the lifting plate drives the photoelectric switch baffle to trigger the photoelectric switch, the pipetting drive unit stops moving.

[0106] 3. Pipetting Unit

[0107] The pipetting unit includes a plunger rod, an airtight plunger, a steady-state airtight cavity, a connecting tube, a TIP head pipe, and a pressure sensor;

[0108] The stable airtight cavity is vertically arranged in the device housing;

[0109] The airtight plunger is arranged in the stable airtight cavity and is adapted to the stable airtight cavity; the outer ring of the airtight plunger is provided with an O-ring to improve the airtightness of the pipetting unit;

[0110] One end of the plunger rod passes through the fixed plate on the device housing and is fixed to the airtight plunger, and the other end is fixed to the lifting plate through a pin shaft, so as to achieve the downward movement of the lifting plate and push the airtight plunger to compress the stable airtight cavity;

[0111] A pressure sensor is provided on the device housing at the lowest position of the corresponding steady-state airtight cavity to monitor the actual pressure P in the steady-state airtight cavity. a and send it to the controller;

[0112] The TIP head pipe is arranged on the bottom surface of the device housing, and the TIP head pipe is connected to the bottom of the stable airtight cavity through a connecting pipe;

[0113] Each TIP head pipe is provided with a pipe withdrawal ring, and the pipe withdrawal ring is clamped in the device housing;

[0114] A return spring is sleeved on the connecting pipe, and one end of the return spring abuts against the auxiliary connecting rod, and the other end abuts against the pipe withdrawal ring;

[0115] When the plunger rod moves downward to the bottom of the airtight cavity, the lifting plate presses down the auxiliary connecting rod, the auxiliary connecting rod compresses the return spring, the return spring compresses the tube withdrawal ring downward, and the tube withdrawal ring moves downward, thereby removing the TIP head;

[0116] An O-ring is also provided on the TIP head pipe to prevent leakage.

[0117] like Figure 3 FIG. 1 is a flowchart of the high-precision pipetting device and method of the present invention. The present invention provides an automatic pipetting method for a high-precision automatic pipetting device for an automated laboratory, comprising the following steps:

[0118] 1) Place the TIP connector against the TIP connector and press the TIP connector onto the connector to complete the installation.

[0119] 2) When the through-type stepper motor receives the action command from the controller, it drives the through-type shaft to move, which in turn drives the plunger rod to move through the lifting plate, thereby changing the volume and pressure of the steady-state airtight chamber. Through air replacement, the pipetting unit completes the functions of aspirating and discharging liquids.

[0120] 3) When the through-axis moves upward, the controller controls the pipetting drive unit through the intelligent setting model of the plunger rod stroke and the high-resolution control of the stepper motor to complete the TIP head pipetting operation;

[0121] 4) When the through-axis moves downward, the liquid dispensing operation of the TIP pipe of the pipetting unit is completed. When the plunger rod moves downward to the bottom of the airtight cavity, the lifting plate presses down the auxiliary connecting rod, which compresses the return spring. The return spring compresses the tube withdrawal ring downward, and the tube withdrawal ring moves downward, thereby removing the TIP from the TIP pipe.

[0122] 5) Repeat steps 1) to 4) to achieve the distribution of multiple liquids.

[0123] The above process automatically dispenses a single liquid. To dispense multiple liquids, simply replace the tip and repeat the process. The tip is the only one in contact with the liquid being dispensed. The disposable tip prevents cross-contamination and eliminates the need for repeated cleaning.

[0124] Specifically, in step 3), the plunger rod stroke intelligent setting model is as follows: a preset value of the plunger rod stroke is obtained based on the actual local atmospheric pressure and the desired pipetting volume; and an auxiliary judgment is made based on the pressure inside the airtight plunger in a steady state to adjust the preset value of the plunger rod stroke;

[0125] The method includes establishing the plunger rod stroke intelligent setting model and completing the motion control of the pipetting drive unit through the controller according to the plunger rod stroke intelligent setting model, including the following steps:

[0126] Assume that the atmospheric pressure is P0, the desired pipetting volume is V, the plunger rod stroke is H, and the corresponding airtight plunger internal pressure is P. P is taken as the ideal steady-state airtight plunger internal pressure.

[0127] For a certain specification of TIP head, with P0 and V as input variables, H as output variable, and P as auxiliary variable, the actual steady-state airtight plunger internal pressure P a As monitoring variables, the whale optimization algorithm-least squares support vector machine method is used to establish a preset model of the plunger rod stroke and an ideal steady-state airtight plunger internal pressure prediction model, namely:

[0128] (1) Let X be the matrix composed of the sample data of the input variables P0 and V, and Y and Z be the matrices composed of the sample data of the corresponding output variables H and auxiliary variables P, respectively. Then:

[0129]

[0130] in, is the data of input variable P0, is the data of input variable V, N is the number of samples; let x i =[x 1i ,x 2i ], represents the input of the i-th sample of the plunger rod stroke preset model and the ideal steady-state airtight plunger internal pressure prediction model, y i represents the output of the i-th sample of the plunger rod stroke preset model, z i represents the output of the i-th sample of the ideal steady-state airtight plunger internal pressure prediction model, i = 1, 2, ..., N;

[0131] (2) Using the whale optimization algorithm-least squares support vector machine method to establish a plunger rod stroke preset model;

[0132] The plunger rod stroke preset model is established using the LSSVM method. The input variables of the model are P0 and V, and the output variable is H. The kernel function in the LSSVM method adopts the form of radial basis function, and the width of the radial basis function is set to σ, and the regularization parameter is γ.

[0133] The vector [σ,γ] composed of σ and γ is used as the position of the whale individual. The positions of several whale individuals are randomly generated. For the parameters σ and γ in each whale individual position, a model is established using sample data and the LSSVM method. The parameters σ and γ in the model are optimized using the whale optimization algorithm. The upper and lower limits of the optimized parameter σ are σ and γ, respectively. max and σ min , the upper and lower limits of γ are γ max and γ min , the parameters σ and γ obtained after optimization are substituted into the LSSVM model to obtain the plunger rod stroke preset model;

[0134] (3) Using the whale optimization algorithm-least squares support vector machine method, an ideal steady-state airtight plunger internal pressure prediction model is established;

[0135] (4) Adjust the plunger rod stroke and complete the motion control of the pipetting drive unit through the controller.

[0136] Specifically, in step (2), the specific modeling method is:

[0137] (2-1) Set the current number of iterations t = 1 and the maximum number of iterations T max =15;

[0138] (2-2) Randomly generate N A = The positions of 20 initial whale individuals, the position of each whale individual is:

[0139] S k (t)=[σ min+rand1(σ max -σ min ),γ min +rand2(γ max -γ min )] T

[0140] Where k = 1, 2, ..., N A , rand1 and rand2 are both random numbers in the range [0, 1], σ max =2 9 , σ min =2 -9 , γ max =10 4 , γ min =10 -4 ;

[0141] (2-3) Based on the position of each whale individual, the corresponding LSSVM model is established using the sample data, where the kernel function is:

[0142]

[0143] Where σ is the width of the radial basis function, x i =[x 1i ,x 2i ], represents the input of the i-th sample, i=1,2,...,N,S k (t)[1] represents S k the first component of (t);

[0144] (2-4) Then the output of the LSSVM model corresponding to the kth whale individual position is:

[0145]

[0146] Solve α by the following formula i and d, that is:

[0147]

[0148] Among them, 1 N =[1,1,...,1] T ,α=[α1,α2,...,α N ] T , α represents the weight parameter vector, Ω represents the matrix composed of kernel functions, Ω i,j =K k (x i ,x j ), i=1,2,...,N, j=1,2,...,N,I Nis the N-order unit matrix, γ is the regularization parameter, d represents the bias parameter, S k (t)[2] represents S k The parameters σ and γ in the LSSVM model corresponding to the kth whale individual position are both given by S k The two components of (t) are given;

[0149] (2-5) According to the position of each whale individual, the fitness function is used:

[0150] Calculate the fitness of the corresponding LSSVM model fit k (t), the whale individual position with the maximum fitness is taken as the optimal whale individual position and recorded as S * (t), determine whether t=T max ;

[0151] (2-6) If satisfied, the position S of the optimal whale individual * (t) is output as the final result and substituted into the LSSVM model. The obtained model is the preset model of the plunger rod stroke. If it is not satisfied, let D k (t) = C k (t)S * (t)-S k (t) represents the position vector between the kth whale individual and the random whale individual; Represents the distance vector between the kth whale individual and the optimal whale individual (i.e., the optimal solution); let A k (t) = 2a(t)r 1k (t)-a(t), a(t) is a parameter that decreases linearly from 2 to 0, and the expression is T max Indicates the maximum number of iterations, r 1k (t) is a random number in the range [0,1], C k (t) = 2r 2k (t), r 2k (t) is a random number in the range [0,1]. Generate a random number β(t) in the range [0,1] and determine whether β(t)≤0.5.

[0152] (2-7) If β(t)≤0.5, then determine whether |A k (t)|<1, if satisfied, then use S k (t+1)=S * (t)-A k (t)D k (t) Update the position of the kth whale individual, if |A k (t)|≥1, then use S k(t+1)=S rand (t)-A k (t)D k (t) Update the position of the kth whale individual, S rand (t) represents the position of a randomly selected individual whale;

[0153] (2-8) If β(t)>0.5, then use Update the position of the kth whale individual; where b is the spiral shape parameter, ranging from [0.6, 0.7]; l represents a random number uniformly distributed within [-1, 1];

[0154] (2-9) Let t = t + 1, and repeat steps (2-3) to (2-8).

[0155] The step (3) is specifically:

[0156] (3-1) The input variables of the model are P0 and V, and the output variable is P. The parameters are modified in the process of establishing the plunger rod stroke preset model, namely:

[0157] Change the maximum number of iterations in step (2-1) to T max =20;

[0158] Modify the random generation in step (2-2) to N A = the positions of 30 initial whale individuals, the upper and lower limits of the parameter to be optimized σ are modified to σ max =2 10 and σ min =2 -10 , the upper and lower limits of γ are modified to γ max =10 5 and γ min =10 -3 ,

[0159] Then the equation that needs to be solved for the LSSVM model coefficient becomes:

[0160]

[0161] Modify the value range of parameter b in step (2-8) to [0.3, 0.5];

[0162] (3-2) Based on the specific method of the plunger rod stroke preset model and the parameters modified in the corresponding modeling process, an ideal steady-state airtight plunger internal pressure prediction model is obtained;

[0163] Step (4) is specifically:

[0164] After adjusting the plunger rod stroke according to the preset value of the plunger rod stroke, the actual steady-state airtight plunger internal pressure Pa Perform auxiliary judgment and calculate the actual steady-state airtight plunger internal pressure P a The difference ΔP between the predicted value P of the ideal steady-state airtight plunger pressure is used to adjust the plunger rod stroke in combination with the plunger rod stroke adjustment rule table.

[0165] Table 1 Plunger rod stroke adjustment rules

[0166]

[0167] Where T1, T2 and T3 are deviation limits; a i (i=1,2,…,6) is the adjustment value of the plunger rod stroke, T1 is in the range of [10,15], T2 is in the range of (15,20], T3 is in the range of (20,25], a1 is in the range of [0.003,0.005), a2 is in the range of [0.002,0.003), a3 is in the range of [0.001,0.002), a4 is in the range of [-0.002,-0.001), a5 is in the range of [-0.003,-0.002), and a6 is in the range of [-0.005,-0.003).

[0168] High-resolution precision control of stepper motors is achieved by controlling the phase currents. The controller specifies the motor's subdivision number, which can be an integer between 4 and 64. Subdivision control is achieved by passing linearly varying currents, with a phase difference of π / 2, through the windings of a two-phase stepper motor under the control of the subdivision number and the timing state.

[0169] By installing a position sensor in front of the cavity, when the through shaft of the stepper motor drives the photoelectric switch baffle to the photoelectric sensor trigger position, the controller sends a stop command to the stepper motor, and the stepper motor stops running, thereby realizing automatic origin retrieval.

[0170] In summary, the present invention provides a high-precision automated pipetting device and method. This device uses a plunger rod to drive an airtight plunger to complete the aspiration and dispensing processes. A return spring, a tube withdrawal ring, and a tip connector facilitate installation and removal of the tip. An airtight cavity and O-ring ensure the airtightness of the tip connection. Intelligent plunger rod stroke control ensures pipetting accuracy. Parallelism of the piston movement is ensured by parallel rails and an auxiliary connecting rod.

[0171] At the same time, in the automatic pipetting method of the present invention, the whale optimization algorithm (WOA) is used to optimize the parameters of the plunger rod stroke preset model and the ideal steady-state airtight column internal pressure prediction model. The WOA algorithm has the advantages of simple mechanism, few parameters and strong optimization ability.

[0172] In addition, the functional units in the various embodiments of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware or in the form of software functional units. The above is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An automatic pipetting method for a high-precision automatic pipetting device for an automated laboratory, characterized in that: The following steps are involved: 1) Place the TIP connector against the TIP connector and press the TIP connector onto the connector to complete the installation. 2) When the through-type stepper motor receives the action command from the controller, it drives the through-type shaft to move, which in turn drives the plunger rod to move through the lifting plate, thereby changing the volume and pressure of the steady-state airtight chamber. Through air replacement, the pipetting unit completes the functions of aspirating and discharging liquids. 3) When the through-axis moves upward, the controller controls the pipetting drive unit through the intelligent setting model of the plunger rod stroke and the high-resolution control of the stepper motor to complete the TIP head pipetting operation; The intelligent plunger rod stroke setting model is as follows: a preset plunger rod stroke value is obtained based on the actual local atmospheric pressure and the desired pipetting volume; and an auxiliary judgment is made based on the pressure inside the airtight plunger in a steady state to adjust the preset plunger rod stroke value; The method includes establishing the plunger rod stroke intelligent setting model and completing the motion control of the pipetting drive unit through the controller according to the plunger rod stroke intelligent setting model, including the following steps: Assume that the atmospheric pressure is P0, the desired pipetting volume is V, the plunger rod stroke is H, and the corresponding airtight plunger internal pressure is P. P is taken as the ideal steady-state airtight plunger internal pressure. For a certain specification of TIP head, with P0 and V as input variables, H as output variable, and P as auxiliary variable, the actual steady-state airtight plunger internal pressure P a As monitoring variables, the whale optimization algorithm-least squares support vector machine method is used to establish a preset model of the plunger rod stroke and an ideal steady-state airtight plunger internal pressure prediction model, namely: (1) Let X be the matrix composed of the sample data of the input variables P0 and V, and Y and Z be the matrices composed of the sample data of the corresponding output variables H and auxiliary variables P, respectively. Then: in, is the data of input variable P0, is the data of input variable V, N is the number of samples; let x i =[x 1i ,x 2i ], represents the input of the i-th sample of the plunger rod stroke preset model and the ideal steady-state airtight plunger internal pressure prediction model, y i represents the output of the i-th sample of the plunger rod stroke preset model, z i represents the output of the i-th sample of the ideal steady-state airtight plunger internal pressure prediction model, i = 1, 2, ..., N; (2) Using the whale optimization algorithm-least squares support vector machine method to establish a plunger rod stroke preset model; The plunger rod stroke preset model is established using the LSSVM method. The input variables of the model are P0 and V, and the output variable is H. The kernel function in the LSSVM method adopts the form of radial basis function, and the width of the radial basis function is set to σ, and the regularization parameter is γ. The vector [σ,γ] composed of σ and γ is used as the position of the whale individual. The positions of several whale individuals are randomly generated. For the parameters σ and γ in each whale individual position, a model is established using sample data and the LSSVM method. The parameters σ and γ in the model are optimized using the whale optimization algorithm. The upper and lower limits of the optimized parameter σ are σ and γ, respectively. max and σ min , the upper and lower limits of γ are γ max and γ min , the parameters σ and γ obtained after optimization are substituted into the LSSVM model to obtain the plunger rod stroke preset model; (3) Using the whale optimization algorithm-least squares support vector machine method, an ideal steady-state airtight plunger internal pressure prediction model is established; (4) Adjusting the plunger rod stroke and completing the motion control of the pipetting drive unit through the controller; 4) When the through-axis moves downward, the liquid discharging operation of the TIP head pipe of the pipetting unit is completed; when the plunger rod moves downward to the bottom of the airtight cavity, the lifting plate presses down the auxiliary connecting rod, which compresses the return spring, and the return spring compresses the tube withdrawal ring downward, and the tube withdrawal ring moves downward, thereby removing the TIP head from the TIP head pipe; 5) Repeat steps 1) to 4) to achieve the distribution of multiple liquids; An automatic pipetting method for a high-precision automatic pipetting device for an automated laboratory is implemented based on a high-precision automatic pipetting device for an automated laboratory, the device comprising: a controller, a device housing, a pipetting drive unit, a pipetting motion unit, and a pipetting unit; The pipetting drive unit is fixed to the device housing and connected to the pipetting motion unit. It is used to receive the motor subdivision number sent by the controller, perform high-subdivision control of the stepping motor, and drive the pipetting motion unit to move in the vertical direction. At the same time, it receives the position trigger signal in real time. When the position trigger signal is detected, the pipetting drive unit stops working. The pipetting motion unit is connected to the pipetting unit and the pipetting drive unit respectively, and is used to be driven by the pipetting drive unit to drive the pipetting unit to move in coordination; The pipetting unit is arranged in the housing of the device and is connected to the pipetting motion unit. It is used to drive the pipetting motion unit to perform the reciprocating motion of the plunger to realize the pipetting operation. At the same time, the actual steady-state pressure P in the airtight cavity is a Send to the controller for processing; The controller is connected to the pipetting drive unit and is used to receive the actual steady-state airtight cavity pressure P sent by the pipetting unit. a , build an intelligent setting model for the plunger rod stroke, and at the same time, send the motor subdivision number to the pipetting drive unit, and combine the stepper motor high subdivision control method to control and adjust the pipetting drive unit.

2. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, characterized in that: The pipetting drive unit includes: a stepping motor, a photoelectric switch and a photoelectric switch baffle; The stepper motor is a through-type stepper motor. The motor body of the stepper motor is fixedly mounted on the device housing. The through-axis of the stepper motor is perpendicular to the top surface of the device housing. One end of the through-axis passes through the motor body and is inserted into a corresponding cavity of the device housing. The other end is fixedly connected to the pipetting motion unit. When the stepper motor receives a command from the controller, it drives the through-axis to move downward and drives the pipetting motion unit to move downward. The photoelectric switch baffle is fixed on the pipetting motion unit, and the photoelectric switch baffle is perpendicular to the horizontal plane and parallel to the through axis; the photoelectric switch baffle corresponds to the position of the photoelectric switch provided on the device housing. When the pipetting motion unit moves downward, it drives the photoelectric switch baffle to insert and trigger the photoelectric switch to receive a position trigger signal. The photoelectric switch sends a stop operation instruction and is connected to the stepper motor to control the stepper motor to stop working.

3. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, characterized in that: The pipetting motion unit includes: a lifting plate, a connecting plate, an auxiliary connecting rod, a slider and a parallel track; The lifting plate is arranged parallel to the horizontal plane and is connected to the through shaft of the pipetting drive unit; a photoelectric switch baffle is fixed on the lifting plate; A fixing plate is provided on the top surface of the device housing below the lifting plate, and a plurality of auxiliary connecting rods are vertically provided on the bottom surface of the lifting plate. The auxiliary connecting rods are slidably arranged in the through holes of the fixing plate and inserted into the cavity provided in the device housing to limit the displacement of the lifting plate; The parallel track is vertically arranged on the device housing, and the arrangement position of the parallel track is located on the same side as the connecting plate; a slider is slidably provided on the parallel track, and the slider is fixedly connected to the connecting plate to limit the displacement of the pipetting motion unit; The pipetting drive unit moves, driving the lifting plate to descend, and the lifting plate is limited in its downward displacement by the connecting plate and the auxiliary connecting rod. When the lifting plate drives the photoelectric switch baffle to trigger the photoelectric switch, the pipetting drive unit stops moving.

4. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, characterized in that: The pipetting unit comprises: a plunger rod, an airtight plunger, a stable airtight cavity, a connecting tube, a TIP head pipe and a pressure sensor; The stable airtight cavity is vertically arranged in the device housing; The airtight plunger is arranged in the stable airtight cavity and is adapted to the stable airtight cavity; the outer ring of the airtight plunger is provided with an O-ring to improve the airtightness of the pipetting unit; One end of the plunger rod passes through the fixed plate on the device housing and is fixedly connected to the airtight plunger, and the other end is fixedly connected to the lifting plate through a pin shaft, so as to achieve the downward displacement of the lifting plate and push the airtight plunger to compress the stable airtight cavity; A pressure sensor is provided on the device housing at the lowest position of the corresponding steady-state airtight cavity to monitor the actual pressure P in the steady-state airtight cavity. a , and will be sent to the controller; The TIP connector is provided on the bottom surface of the device housing, and is connected to the bottom of the stable airtight cavity through a connecting pipe; The TIP head pipe is provided with a pipe withdrawal ring, and the pipe withdrawal ring is clamped in the device housing; A return spring is sleeved on the connecting pipe, and one end of the return spring abuts against the auxiliary connecting rod, and the other end abuts against the pipe withdrawal ring; When the plunger rod moves downward to the bottom of the airtight cavity, the lifting plate presses down the auxiliary connecting rod, the auxiliary connecting rod compresses the return spring, the return spring compresses the tube withdrawal ring downward, and the tube withdrawal ring moves downward, thereby removing the TIP head; An O-type sealing ring is also sleeved on the TIP head pipe to prevent leakage.

5. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, characterized in that: The step (2) is specifically: (2-1) Set the current number of iterations t = 1 and the maximum number of iterations T max =15; (2-2) Randomly generate N A = The positions of 20 initial whale individuals, the position of each whale individual is: S k (t)=[σ min +rand1(s max -s min ),c min +rand2(c max -c min )] T Where k = 1, 2, ..., N A , rand1 and rand2 are both random numbers in the range [0, 1], σ max =2 9 ,σ min =2 -9 , γ max =10 4 , γ min =10 -4 ; (2-3) Based on the position of each whale individual, the corresponding LSSVM model is established using the sample data, where the kernel function is: Where σ is the width of the radial basis function, x i =[x 1i ,x 2i ], represents the input of the i-th sample, i=1,2,...,N,S k (t)[1] represents S k the first component of (t); (2-4) Then the output of the LSSVM model corresponding to the kth whale individual position is: Solve α by the following formula i and d, that is: Among them, 1 N =[1,1,...,1] T ,α=[α1,α2,...,α N ] T , α represents the weight parameter vector, Ω represents the matrix composed of kernel functions, Ω i,j =K k (x i ,x j ), i=1,2,...,N, j=1,2,...,N,I N is the N-order unit matrix, γ is the regularization parameter, d represents the bias parameter, S k (t)[2] represents S k The second component of (t), the parameters σ and γ in the LSSVM model corresponding to the kth whale individual position are both given by S k The two components of (t) are given; (2-5) According to the position of each whale individual, the fitness function is used: Calculate the fitness of the corresponding LSSVM model fit k (t), the whale individual position with the maximum fitness is taken as the optimal whale individual position and recorded as S * (t), determine whether t=T max ; (2-6) If satisfied, the position S of the optimal whale individual * (t) is output as the final result and substituted into the LSSVM model. The obtained model is the preset model of the plunger rod stroke. If it is not satisfied, let D k (t) = C k (t)S * (t)-S k (t) represents the position vector between the kth whale individual and the random whale individual; Represents the distance vector between the kth whale individual and the optimal whale individual (i.e., the optimal solution); let A k (t) = 2a(t)r 1k (t)-a(t), a(t) is a parameter that decreases linearly from 2 to 0, and the expression is T max Indicates the maximum number of iterations, r 1k (t) is a random number in the range [0,1], C k (t) = 2r 2k (t), r 2k (t) is a random number in the range [0,1]. Generate a random number β(t) in the range [0,1] and determine whether β(t)≤0.

5. (2-7) If β(t)≤0.5, then determine whether |A k (t)|<1, if satisfied, then use S k (t+1)=S * (t)-A k (t)D k (t) Update the position of the kth whale individual, if |A k (t)|≥1, then use S k (t+1)=S rand (t)-A k (t)D k (t) Update the position of the kth whale individual, S rand (t) represents the position of a randomly selected individual whale; (2-8) If β(t)>0.5, then use Update the position of the kth whale individual; where b is the spiral shape parameter, ranging from [0.6, 0.7]; l represents a random number uniformly distributed within [-1, 1]; (2-9) Let t = t + 1, and repeat steps (2-3) to (2-8).

6. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, wherein the step (3) is specifically: (3-1) The input variables of the model are P0 and V, and the output variable is P. The parameters are modified in the process of establishing the plunger rod stroke preset model, namely: Change the maximum number of iterations in step (2-1) to T max =20; Modify the random generation in step (2-2) to N A = the positions of 30 initial whale individuals, the upper and lower limits of the parameter to be optimized σ are modified to σ max =2 10 and σ min =2 -10 , the upper and lower limits of γ are modified to γ max =10 5 and γ min =10 -3 , Then the equation that needs to be solved for the LSSVM model coefficient becomes: Modify the value range of parameter b in step (2-8) to [0.3, 0.5]; (3-2) Based on the specific method of the plunger rod stroke preset model and combined with the parameters modified in the corresponding modeling process, an ideal steady-state airtight plunger internal pressure prediction model is obtained.

7. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, wherein the step (4) is specifically: After adjusting the plunger rod stroke according to the preset value of the plunger rod stroke, the steady-state airtight plunger internal pressure P a Perform auxiliary judgment and calculate the actual steady-state airtight plunger internal pressure P a The difference ΔP between the predicted value P of the ideal steady-state airtight plunger pressure is used to adjust the plunger rod stroke in combination with the plunger rod stroke adjustment rule table.

8. The automatic pipetting method of a high-precision automatic pipetting device for an automated laboratory according to claim 1, wherein the stepping motor is controlled with high subdivision precision, specifically: The controller sends the motor subdivision number to the pipetting drive unit, where The value of the subdivision number is an integer between 4 and 64; Under the control of the subdivision number and timing state, two-phase linearly changing currents with a difference of π / 2 are passed through the windings of the two-phase stepper motor, thereby realizing subdivision control.

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