CN115575560A - Automatic titration sample loading machine - Google Patents

Abstract

The invention discloses an automatic loading machine and an automatic loading method for a titration sample, which comprise a loading mechanical arm (1), a lifting tower (2), a rotating base (3) and a beaker frame (4), wherein the loading mechanical arm (1) clamps and transports a sample beaker, the lifting tower (2) is connected with the loading mechanical arm (1) to control the lifting of the loading mechanical arm (1), the rotating base (3) is positioned at the lower end of the lifting tower (2) and can drive the lifting tower (2) to rotate, and the sample beaker frame (4) contains a sample beaker to be tested. This automatic sample loading machine can realize that the sample of batch is automatic to discern different types of sample and beaker, centre gripping transportation safety and stability, no shake.

Description

Automatic sample loading machine for titration sample

Technical Field

The invention relates to an automatic sample loading machine for a titration sample, and belongs to the technical field of titration detection.

Background

Traditional titration equipment needs to place the titration sample on the titration analysis platform manually, and this kind of mode is only applicable to the less laboratory of sample quantity, and to detecting in batches on the industrial production assembly line, uses the mode of artifical appearance of going up, has not only increased personnel's intensity of labour, still drags slow detection speed, influences the efficient operation that lasts of production assembly line.

Therefore, it is necessary to design an automatic titration sample loading machine to assist the continuous sample loading titration detection.

Disclosure of Invention

In order to overcome the problems, the inventor of the invention carries out intensive research to design an automatic titration sample loading machine, which comprises a loading mechanical arm 1, a lifting tower 2, a rotating base 3 and a beaker frame 4,

the sample loading mechanical arm 1 clamps and transports a sample beaker;

the lifting tower 2 is connected with the sample loading mechanical arm 1 and controls the lifting of the sample loading mechanical arm 1;

the rotating base 3 is positioned at the lower end of the lifting tower 2 and can drive the lifting tower 2 to rotate;

the sample beaker frame 4 holds a sample beaker to be measured.

In a preferred embodiment, the sample loading mechanical arm 1 comprises a grabber 11, a rotating arm 12 and a fixed arm 13, one end of the rotating arm 12 is connected with the fixed arm 13 through a rotating joint 14, so that the rotating arm 12 can rotate relative to the fixed arm 13, and the grabber is mounted at the other end of the rotating arm 12.

In a preferred embodiment, the gripper 11 includes a gripping head holder 111, a gripping motor 112, a double-threaded screw 113, and two sample jaws 114, the gripping head holder 111 is fixedly connected to the rotating arm 12, the gripping motor 112 is fixed below the gripping head holder 111, an output shaft of the gripping motor 112 is connected to the double-threaded screw 113, and the two sample jaws 114 are respectively fixedly connected to two nuts on the double-threaded screw 113

In a preferred embodiment, the lower end of the sample jaw 114 is provided with a pressure sensor 116, and the change of the strain force when the sample jaw 114 contacts the beaker is detected by the pressure sensor 116.

In a preferred embodiment, the rotary joint 14 includes a driving motor 141 and a reduction gear box 142, the driving motor 141 is mounted on the fixed arm 13, the reduction gear box 142 is fixedly connected to the rotating arm 12, an output shaft of the driving motor 141 is connected to the reduction gear box 142, and rotation of the rotating arm 12 relative to the fixed arm 13 is achieved by rotation of the driving motor 141.

In a preferred embodiment, the rotary joint 14 further comprises an angle sensor 143, and the angle sensor 143 is coaxial with a rotation axis of the rotary arm 12 when rotating relative to the fixed arm 13.

In a preferred embodiment, the beaker frame 4 comprises a base 41 and a tray 42 placed on the base 41, and one or more beaker holes are provided on the tray 42.

In a preferred embodiment, a permanent magnet 421 is provided on the bottom of the tray 42, and a linear magnetic detection sensor 411 is provided on the base 41, the permanent magnet 421 corresponding to the position of the linear magnetic detection sensor.

In another aspect, the present invention also provides a method for automatically loading a titration sample, preferably by the automatic titration sample loading machine of any one of claims 1 to 8, comprising the steps of:

s1, obtaining the specification of a beaker;

s2, clamping the beaker to a titration analysis platform.

In a preferred embodiment, in step S2, compliance control is adopted during the process of gripping and transferring the beaker, wherein the compliance control during the process of transferring the beaker is used for controlling the linear stage of the output process of the driving motor, the control comprises position closed-loop control, speed closed-loop control and moment flexible closed-loop control,

the position closed-loop control means that the angular position PI is adjusted through the angular position detected by the rotary joint angle sensor;

in the speed closed-loop control, differentiating the detection value of a rotary joint angle sensor to obtain an angular speed measurement value, carrying out speed PID (proportion integration differentiation) regulation by taking the angular speed measurement value as a feedback signal and taking the output value of position PI regulation as a target value, and outputting a torque value of a driving motor;

in the moment flexible closed-loop control, the output value of speed PID regulation is taken as a target value, the linear predicted value of the output moment of the driving motor is taken as a feedback signal, moment PI regulation is carried out, and the quantity of stepping pulses of the driving motor and the level of direction control are output.

The invention has the advantages that:

(1) Batch automatic sample loading can be realized;

(2) Different types of samples and beakers can be identified;

(3) The clamping and transferring process is safe and stable without shaking.

Drawings

FIG. 1 is a schematic diagram showing the overall structure of an automatic loading machine for a titration sample according to a preferred embodiment of the present invention;

FIG. 2 shows a schematic diagram of an automatic loading robot arm for titrating samples according to a preferred embodiment of the invention;

FIG. 3 shows a schematic diagram of an automatic loading grabber for a titration sample onto a prototype according to a preferred embodiment of the present invention;

FIG. 4 is a schematic diagram showing the construction of an automatic loading grabber for a titration sample according to a preferred embodiment of the present invention;

FIG. 5 shows a schematic view of a rotary joint structure of an automatic sample loading machine for titration samples according to a preferred embodiment of the invention;

FIG. 6 shows a schematic diagram of a structure of a lifting tower for automatically loading a titration sample onto a prototype according to a preferred embodiment of the present invention;

FIG. 7 shows a schematic diagram of a structure of a titer sample autosampler beaker frame according to a preferred embodiment of the invention;

FIG. 8 is a schematic diagram illustrating a gripping motor rotation feedback adjustment algorithm in an automatic loading method for a titration sample according to a preferred embodiment of the present invention;

FIG. 9 is a graph showing the relationship between the number of moving steps of the driving motor and the pressure sensor;

fig. 10 shows a schematic diagram of the compliance control method during transferring the beaker in the automatic loading method of the titration sample according to a preferred embodiment of the present invention.

The reference numbers indicate:

1-a mechanical arm;

11-a gripper;

111-a gripper bar;

112-a grasping motor;

113-double thread lead screw;

114-sample jaw;

115-a position sensor;

116-a pressure sensor;

12-a rotating arm;

13-a fixed arm;

14-a rotary joint;

141-a drive motor;

142-a reduction gearbox;

143-angle sensor;

2-a lifting tower;

21-a tower base;

22-lead screw elevator;

23-a limit switch;

24-a linear displacement sensor;

3-rotating the base;

4-a beaker holder;

41-a base;

411-linear magnetic detection sensor;

42-a tray;

421-a permanent magnet;

422-beaker;

423-beaker identification module.

Detailed Description

The invention is explained in more detail below with reference to the figures and examples. The features and advantages of the present invention will become more apparent from the description.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The invention provides an automatic titration sample loading machine which comprises a loading mechanical arm 1, a lifting tower 2, a rotating base 3 and a beaker frame 4, and is shown in figure 1.

The sample loading mechanical arm 1 clamps and transports a sample beaker;

the lifting tower 2 is connected with the sample loading mechanical arm 1 and controls the lifting of the sample loading mechanical arm 1;

the rotating base 3 is positioned at the lower end of the lifting tower 2 and can drive the lifting tower 2 to rotate;

the sample beaker frame 4 holds a sample beaker to be measured.

Further, the loading robot arm 1 includes a gripper 11, a rotating arm 12, and a fixing arm 13, as shown in fig. 2.

One end of the rotating arm 12 is connected with the fixed arm 13 through a rotating joint 14, so that the rotating arm 12 can rotate relative to the fixed arm 13, and the gripper is mounted at the other end of the rotating arm 12.

In the invention, three-degree-of-freedom joint motion is provided through the lifting tower 2, the rotating base 3 and the rotating joint 14, so that the grabber 11 can accurately grab the beaker in a larger range. Specifically, the lifting tower 2 is rotated by the rotation of the rotating base 3, and the rotating arm 12 can also rotate while the fixed arm 13 rotates or lifts along with the lifting tower 2, and the rotation of the fixed arm and the rotating arm can enable the grabber 11 to reach any position in the working area of the grabber.

Because the outer surface of the beaker is often soaked and stuck with a sample to be measured, the surface friction is low, and therefore, the grabber needs to have a large effective clamping contact area with the beaker when grabbing the beaker.

Furthermore, the beaker is generally made of glass or plastic, and has low mechanical strength, so that the beaker is easily damaged if the clamping force is high, and the beaker slides in the clamping process if the clamping force is low, which has a high requirement on the holding pressure of the gripper.

In the present invention, the gripper 11 comprises a gripper head frame 111, a gripper motor 112, a double-threaded lead screw 113 and two sample jaws 114, as shown in fig. 3.

The grabbing headstock 111 is fixedly connected with the rotating arm 12, the grabbing motor 112 is fixed below the grabbing headstock 111, an output shaft of the grabbing motor 112 is connected with the double-threaded lead screw 113, and the two sample clamping jaws 114 are respectively and fixedly connected with two nuts on the double-threaded lead screw 113.

The double-thread screw is a screw with two threads with different screwing directions, the two threads are respectively provided with a nut, and when the screw rotates, the two nuts approach or separate, so that the clamping and loosening functions of the sample clamping jaw are realized.

Further, in accordance with the present invention, the grasping motor 112 is a stepper motor to control the degree of clamping and unclamping of the sample jaws.

The lower end of the sample clamping jaw 114 is plate-shaped or finger-shaped, preferably, the lower end of the sample clamping jaw 114 is provided with a pressure sensor 116, and the change of the strain force when the sample clamping jaw 114 is contacted with the beaker is detected by the pressure sensor 116, so as to determine the clamping force of the sample clamping jaw.

Preferably, a film pressure sensor is arranged at the contact position of the lower end of the sample clamping jaw 114 and the beaker, the pressure value of the reagent cup grabbed by the mechanical claw is obtained through the film pressure sensor, and then the angle of the sample clamping jaw is adjusted all the time, so that the effect of constantly controlling the grabbing force of the reagent cups with different diameters is realized.

Due to the arrangement of the pressure sensor, the sample clamping jaw 114 can adapt to beakers of different specifications, compared with the method that the clamping amount is controlled by simply controlling the mechanical size during clamping, the tolerance of the tension sensor on the size deformation of the beaker is high, and the method is particularly suitable for batch detection during industrial production.

In a preferred embodiment, a plurality of position sensors 115, preferably two end position sensors, are disposed on the gripping head frame 111, symmetrically disposed at two ends of the sample clamping jaw 114 with the center line of the two sample clamping jaws 114 as a symmetry axis, as shown in fig. 4, as a limit detection of the sample clamping jaw 114 when it is opened,

further, when the two sample clamping jaws 114 cannot simultaneously start the end sensors after being opened, the center line of the sample clamping jaw 114 is changed, and an operator can be reminded to perform inspection and maintenance.

In a more preferred embodiment, the position sensor 115 further comprises a center position sensor disposed at the center of the double threaded screw 113 for detecting whether the sample jaw 114 returns to the center of the double threaded screw 113 when closed.

The rotary joint 14 includes a driving motor 141 and a reduction gear box 142, the driving motor 141 is mounted on the fixed arm 13, the reduction gear box 142 is fixedly connected to the rotary arm 12, an output shaft of the driving motor 141 is connected to the reduction gear box 142, and rotation of the rotary arm 12 relative to the fixed arm 13 is achieved by rotation of the driving motor 141, as shown in fig. 5.

Further, the driving motor 141 is a stepping motor, and the rotation amount of the rotating arm 12 relative to the fixed arm 13 is adjusted by adjusting the rotation amount of the stepping motor 141.

Further, the application of the reduction gear box 142 reduces the power requirement on the driving motor 141, reduces the influence of the rotation loss of the driving motor 141 on the rotation amount, and ensures the rotation accuracy of the rotating arm 12.

More preferably, the driving motor 141 is a closed-loop stepping motor, such as a 57HSXX series, and a mechanical angle sensor is provided inside the closed-loop stepping motor, so that the number of stepping rotation steps can be counted, an output torque can be formed, flexible control can be performed during the transportation process, and the sample is prevented from overflowing from the beaker opening due to severe vibration.

Preferably, the rotary joint 14 further includes an angle sensor 143, the angle sensor 143 is coaxial with a rotation axis of the rotary arm 12 when rotating relative to the fixed arm 13, after the rotary arm rotates for multiple times, a rotation error may be accumulated, calibration of a rotation position can be achieved through the angle sensor 143, an error is reduced, rotation accuracy of the rotary arm 12 is further ensured, and a sufficient margin is left for repeated positioning accuracy.

The lifting tower 2 comprises a tower base 21 and a lead screw lifter 22, and the fixed arm 13 is lifted and lowered by the lead screw lifter 22, as shown in fig. 6.

The tower base 21 is used for supporting, the lead screw lifter 22 is installed on the tower base 21, and preferably, a limit switch 23 is arranged on the tower base 21 to detect or limit the lifting height of the fixing arm 13.

The limit switch 23 may be a travel switch, a limit switch, or any other structure or device capable of detecting a travel, preferably an optoelectronic switch.

In a more preferred embodiment, a linear displacement sensor 24 is further provided on the tower 21 along the lead screw direction of the lead screw elevator 22 to detect the height of the fixing arm 13 in real time.

The rotating base 3 is arranged at the bottom of the lifting tower 2 and drives the lifting tower 2 to rotate.

Preferably, an angle sensor is provided on the rotating base 3 to detect the rotation angle of the elevating tower 2.

The beaker frame 4 is used for storing beakers, is convenient for the sample loading mechanical arm 1 to clamp and store, and comprises a base 41 and a tray 42 arranged on the base 41, and is shown in fig. 7.

In the invention, the automatic titration sample loading machine is used for large-batch sample detection, and the difficulty is that how to distinguish the types of samples to be detected in the face of different samples to be detected, so that a titrator can select a proper titration program according to the types of the samples to be detected.

In the invention, the beakers containing different types of samples to be detected are placed in different trays 42, and the types of the samples to be detected are distinguished by detecting the types or the numbers of the trays 42.

Specifically, one or more beaker holes are provided in the tray 42 for placing the beakers 422.

The inventor finds that different samples to be detected need different dosage in detection, so the dosage needs to be set according to the types of the samples to be detected

The tray 42 may have a plurality of trays, and the sizes of the beaker holes formed in different trays 42 may be different to accommodate beakers of different sizes.

According to a preferred embodiment of the present invention, different kinds of samples to be tested are placed in beakers of different specifications.

In the present invention, the type of sample to be tested in the beaker on the tray is determined by testing different trays 42.

Further, a permanent magnet 421 is provided at the bottom of the tray 42, a linear magnetic detecting sensor 411 is provided on the base 41, and the permanent magnet 421 corresponds to the position of the linear magnetic detecting sensor, so that the linear magnetic detecting sensor 411 can detect the magnetism of the permanent magnet 421, judge whether the tray 42 is placed on the base 41 by the detected magnetism, and judge the specification or number of the tray 42.

Preferably, the permanent magnet and the linear magnetic detection sensor have a plurality of, for example two, downward facing magnetic poles of different permanent magnets may be different, so that the magnetic poles of different trays 42 detected by the linear magnetic detection sensor 411 are different, thereby distinguishing different trays, and further, 2 can be distinguished in this way ^N The tray specification, N, indicates the number of permanent magnets.

For example, the trays of three specifications are provided, each of the trays of three specifications is provided with two permanent magnets, the downward magnetic poles of the two permanent magnets of the tray of the first specification are both N, one of the downward magnetic poles of the two permanent magnets of the tray of the second specification is S, the other is N, and the downward magnetic poles of the two permanent magnets of the tray of the third specification are both S.

In a preferred embodiment, the linear magnetic detecting sensor 411 is a hall sensor, and the hall sensor can detect the magnetic pole of the magnet and convert the magnetic pole into a voltage signal, for example, when the three trays are all placed on the base, the detection voltage of the two hall sensors is 0; when the tray with the first specification is placed on the base, the detection voltages of the two Hall sensors are negative voltages; when the tray with the second specification is placed on the base, the detection voltages of the two Hall sensors are respectively positive voltage and negative voltage; when the tray of the third specification is placed on the base, the detection voltages of the two hall sensors are both negative voltages.

In a preferred embodiment, when there are a plurality of permanent magnets 421 at the bottom of the tray 42, one or more of the permanent magnets 421 may be replaced by a non-magnetic substance, and at this time, only the detection result of the linear magnetic detection sensor corresponding to the non-magnetic substance is 0, and the detection results of the linear magnetic detection sensors corresponding to the remaining permanent magnets are magnetic poles, and in cooperation with each other, the specification of the tray can still be identified, and the number capable of representing the type or number of the tray is expanded without increasing the number of permanent magnets, by which 3 can be distinguished ^N 1 pallet format, N represents the number of permanent magnets.

The inventor finds that in the process of assembly line detection, the tray is difficult to be accurately placed at the specified position of the base every time, and relative deviation often occurs, so that the repeatability of the position of the beaker on the tray is poor, and a large positioning error and influence are caused when the gripper 11 grips the beaker.

In a preferred embodiment, the relative position deviation of the tray and the base can be judged according to the detected magnetic value, so that correction parameters are provided for accurate positioning of the gripping position by the sample loading mechanical arm.

The position of tray on the base removes, can drive the removal in permanent magnet 421 magnetic field to arouse the numerical value change of linear magnetic detection sensor 411 on the base, the tray is in different positions, and different linear magnetic detection sensor 411 numerical relation is different on the base, can confirm the relative position deviation of tray and base through detecting different linear magnetic detection sensor 411 numerical relation on the base.

In a preferred embodiment, the relative positional deviation of the tray from the base is obtained by:

step one, deviation calibration;

the deviation calibration is carried out before actual use, the tray is placed at different positions of the base, so that relative position deviation exists between the tray and the base, the numerical values of the linear magnetic detection sensors under the relative position deviation are obtained, the positional deviation and the numerical values of the linear magnetic detection sensors are recorded, and the process is repeated to obtain the detection numerical values of the linear magnetic detection sensors under different relative position deviations;

more preferably, the plurality of linear magnetic detection sensors detect differences between the values of the plurality of linear magnetic detection sensors at different relative positional deviations, and the relative positional deviation-magnetic induction sensor differences are recorded as a set of values.

Preferably, the obtained sets of values are tabulated or fitted to formulas, curves.

And step two, estimating deviation.

And in the using process, substituting the numerical values of the plurality of linear magnetic detection sensors into the table, the formula or the curve obtained in the step one to obtain the corresponding relative position deviation.

According to a preferred embodiment of the present invention, the upper surface of the base 41 has an area larger than that of the lower surface of the tray, so that a plurality of trays 42 can be placed on the base 41.

According to the invention, the sizes of the bottom surfaces of the trays with different specifications can be different so as to adapt to beakers with different specifications.

In a preferred embodiment, a mark is arranged on the beaker, and a beaker identification module 423 is arranged at the bottom or the side of the beaker hole to read the mark on the beaker, so that the existence state of the beaker can be monitored on line at each sample position, and the sample information can be fed back in real time.

Preferably, the identification is an RFID tag and the beaker identification module 423 is an RFID transceiver.

In another aspect, the present invention further provides an automatic loading method for a titration sample, preferably implemented by the above loading machine, including the following steps:

s1, obtaining the specification of a beaker;

s2, clamping the beaker to a titration analysis platform.

In step S1, a beaker containing a sample to be tested is placed in a tray having a beaker hole matching the beaker, and the tray is placed on a base.

Further, the specification of the beaker is acquired through the detection of the tray.

Specifically, the type of the permanent magnet at the bottom of the tray is detected through the linear magnetic detection sensor, so that the specification or the number of the tray is determined, the specification of the beaker on the tray is determined according to the specification or the number of the tray, and the type of the sample to be detected is determined.

Preferably, the beaker identification module is used for acquiring whether a beaker exists in the beaker hole on the tray, and if the beaker exists, acquiring the number of the beaker or the sample information in the beaker so as to inform the titration analysis platform.

In step S2, the distance between the two sample jaws when the gripper opens and grips is determined according to the specification or number of the beaker.

Furthermore, the position of the grabber during clamping is determined according to the type or the serial number of the tray, and the upper mechanical arm 1, the lifting tower 2 and the rotating base 3 are matched with each other to clamp and transfer the beaker to the titration analysis platform.

The invention aims at the titration detection of batch samples, the transfer speed needs to be improved as much as possible when transferring sample beakers, and meanwhile, the samples in the beakers possibly have the physical and chemical properties of corrosivity, toxicity and the like, so that the sample shaking amount in the beakers needs to be ensured to be small in the transfer process, and the sample is prevented from overflowing from the beakers.

In the invention, the process of clamping and transporting the beaker is flexibly controlled.

Specifically, the compliance control in the gripping process comprises the following substeps:

s21, the distance between the two sample clamping jaws of the grabber is shrunk until the two sample clamping jaws touch the beaker;

s22, detecting the pressure of the contact position of the sample clamping jaws and the beaker, and adjusting the clamping distance between the two sample clamping jaws according to the detected pressure value.

In step S22, the detected value of the pressure is compared with the set value of the gripping pressure, and the rotation of the gripping motor 112 is adjusted to control, so as to achieve stable gripping of the beaker.

Furthermore, the set values of the clamping pressures of the beakers with different specifications are different, and the set values can be obtained by looking up a table according to the corresponding beaker specification obtained in the step S1.

In a preferred embodiment, the rotation of the grabbing motor 112 is adjusted by a feedback adjustment algorithm, as shown in fig. 8, a pressure setting value is subtracted from a measured pressure value to obtain a pressure error value, a rotation step number of the grabbing motor 112 is obtained by a PI adjustment algorithm, the pressure value is measured again after the grabbing motor 112 rotates to obtain a new pressure error value, and the above process is repeated until the pressure error value is less than ± 0.1N.

Preferably, the proportional coefficient kp in the PI regulation algorithm is 0.10-10.00, and the integral time constant ki is 10.0-100.0.

In the process of transferring the beaker, a driving motor in a rotary joint has a starting process and a stopping process, the output torque in the starting process can be gradually increased to a rated value from 0, the output torque in the stopping process is reduced to 0 from the rated value, and the step-out phenomenon is frequently generated in the change process of the output torque and is the main reason for causing the shaking of the beaker in the transferring process.

In the present invention, the starting process of the driving motor is taken as an example for explanation, and the stopping process of the driving motor is similar to the starting process, which is not described in detail.

The relationship between the number of moving steps (unit pulse: 10) of the driving motor and the pressure sensor during the starting process is shown in fig. 9, and it can be seen from the figure that the output process of the driving motor can be divided into a linear stage, a saturation stage and a stable stage.

Wherein, the rotation angle of the linear stage rotating arm 12 relative to the fixed arm 13 is 2 degrees to 2.5 degrees, the rotation angle of the saturated stage rotating arm 12 relative to the fixed arm 13 is 2.5 degrees to 3.5 degrees, and the stable stage is obtained after the saturated stage.

Further, in the linear phase, the relationship between the number of drive motor pulses and the rotational torque may be fitted to a step-torque curve.

Further, the inventor finds that the step-out phenomenon mainly occurs in a linear stage, and the compliance control in the process of transferring the beaker refers to control of the linear stage of the output process of the driving motor, wherein the control includes position closed-loop control, speed closed-loop control and moment flexible closed-loop control, as shown in fig. 10.

Specifically, the position closed-loop control means that in the starting process and the stopping process, the driving motor is not controlled in a conventional rotation step number mode in a linear stage, and the angular position PI is adjusted through the angular position detected by the rotary joint angle sensor, so that the rotation position of the driving motor is controlled.

Further, the target value of the position PI adjustment is a linear stage angle set value, preferably, the linear stage angle set value is 2 to 2.5 degrees; the feedback of the position PI regulation is the detection value of the rotary joint angle sensor, and the output value of the position PI regulation is the rotation angular velocity value of the rotary joint.

Preferably, the value of the proportionality coefficient in the position PI regulation is 0.01-10.00, and the value of the integral time constant is 10.00-100.00.

In the speed closed-loop control, the detection value of the rotary joint angle sensor is differentiated to obtain an angular speed measurement value, the angular speed measurement value is used as a feedback signal, the output value of position PI regulation is used as a target value, speed PID regulation is carried out, and a torque value of a driving motor is output.

Preferably, the proportional coefficient in the speed PID adjustment is 0.01-100.00, and the integral time constant is 10.00-300.00.

In the moment flexible closed-loop control, the output value of speed PID regulation is taken as a target value, the linear predicted value of the output moment of the driving motor is taken as a feedback signal, moment PI regulation is carried out, and the quantity of stepping pulses of the driving motor and the level of direction control are output.

The linear predicted value of the output torque of the driving motor is obtained by substituting the pulse number of the driving motor into a step number-torque curve.

Preferably, the value of the proportional coefficient in the torque PI regulation is 0.01-1000.00, and the value of the integral time constant is 10.00-1000.00.

Under the three-stage series closed-loop control, the mechanical arm can be controlled flexibly, shaking cannot be generated in the moving process of the beaker, and the fluctuation of the liquid level of a sample in the beaker is not more than 1ml in the transferring process.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", and the like indicate orientations or positional relationships based on operational states of the present invention, and are only used for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise specifically stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the connection may be direct or indirect through an intermediate medium, and the connection may be internal to the two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

The present invention has been described above in connection with preferred embodiments, which are merely exemplary and illustrative. On the basis of the above, the invention can be subjected to various substitutions and modifications, and the substitutions and the modifications are all within the protection scope of the invention.

Claims (10)

1. An automatic titration sample loading machine is characterized by comprising a loading mechanical arm (1), a lifting tower (2), a rotating base (3) and a beaker frame (4),

the sample loading mechanical arm (1) is used for clamping and transferring a sample beaker;

the lifting tower (2) is connected with the sample loading mechanical arm (1) and controls the lifting of the sample loading mechanical arm (1);

the rotating base (3) is positioned at the lower end of the lifting tower (2) and can drive the lifting tower (2) to rotate;

the sample beaker frame (4) is used for holding a sample beaker to be detected.

2. The automatic titration sample proofing machine according to claim 1,

the sample loading mechanical arm (1) comprises a grabber (11), a rotating arm (12) and a fixing arm (13), one end of the rotating arm (12) is connected with the fixing arm (13) through a rotating joint (14), so that the rotating arm (12) can rotate relative to the fixing arm (13), and the grabber is installed at the other end of the rotating arm (12).

3. The automatic loading machine for titration sample according to claim 1,

the grabber (11) comprises a grabbing headstock (111), a grabbing motor (112), a double-threaded lead screw (113) and two sample clamping jaws (114), the grabbing headstock (111) is fixedly connected with the rotating arm (12), the grabbing motor (112) is fixed below the grabbing headstock (111), an output shaft of the grabbing motor (112) is connected with the double-threaded lead screw (113), and the two sample clamping jaws (114) are fixedly connected with two nuts on the double-threaded lead screw (113) respectively.

4. The automatic titration sample proofing machine according to claim 3,

the lower end of the sample clamping jaw (114) is provided with a pressure sensor (116), and the change condition of the strain force when the sample clamping jaw (114) is contacted with the beaker is detected through the pressure sensor (116).

5. The automatic titration sample proofing machine according to claim 2,

the rotary joint (14) comprises a driving motor (141) and a reduction gear box (142), the driving motor (141) is installed on the fixing arm (13), the reduction gear box (142) is fixedly connected with the rotating arm (12), an output shaft of the driving motor (141) is connected with the reduction gear box (142), and the rotating arm (12) rotates relative to the fixing arm (13) through the rotation of the driving motor (141).

6. The automatic titration sample proofing machine according to claim 2,

the rotary joint (14) further comprises an angle sensor (143), and the angle sensor (143) is coaxial with a rotating shaft when the rotating arm (12) rotates relative to the fixed arm (13).

7. Automatic titration sample proofing machine according to one of claims 1 to 6,

the beaker frame (4) comprises a base (41) and a tray (42) placed on the base (41), wherein one or more beaker holes are formed in the tray (42).

8. The automatic titration sample proofing machine according to claim 7,

the bottom of the tray (42) is provided with a permanent magnet (421), the base (41) is provided with a linear magnetic detection sensor (411), and the position of the permanent magnet (421) corresponds to that of the linear magnetic detection sensor.

9. An automatic titration sample loading method, preferably realized by the automatic titration sample loading machine according to any one of claims 1 to 8, comprising the following steps:

s1, obtaining the specification of a beaker;

s2, clamping the beaker to a titration analysis platform.

10. The method for automatically loading a titration sample according to claim 9,

in the step S2, compliance control is adopted in the process of clamping and transferring the beaker, wherein the compliance control in the process of transferring the beaker refers to control of a linear stage of the output process of a driving motor, and the control comprises position closed-loop control, speed closed-loop control and moment flexible closed-loop control,

the position closed-loop control means that the angular position PI is adjusted through the angular position detected by the rotary joint angle sensor;

in the speed closed-loop control, differentiating the detection value of the rotary joint angle sensor to obtain an angular speed measurement value, carrying out speed PID regulation by taking the angular speed measurement value as a feedback signal and taking the output value of position PI regulation as a target value, and outputting a torque value of a driving motor;

in the moment flexible closed-loop control, the output value of speed PID regulation is taken as a target value, the linear predicted value of the output moment of the driving motor is taken as a feedback signal, moment PI regulation is carried out, and the quantity of stepping pulses of the driving motor and the level of direction control are output.

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