A Structure and Method for Controlling the Movement of a Micromanipulation Cell Probe

Abstract

The present invention belongs to the technical field of cell probes, and particularly relates to a structure and method for controlling the movement of a micromanipulation cell probe. The device of the present invention includes a driving mechanism arranged at the output end of a three-axis robotic arm. The driving mechanism includes an R driving shaft and a T driving shaft. The cell probe is installed at the output end of the T driving shaft. Both the three-axis robotic arm and the driving mechanism are electrically connected to a host computer. The host computer controls the movement of the cell probe by controlling the three-axis robotic arm and the driving mechanism. The method of the present invention includes: power-on and homing: marking the absolute positions of the motors of the three-axis robotic arm and the driving mechanism as zero points; host computer control: controlling the movement of the motors of the three-axis robotic arm and the driving mechanism through the host computer; handle control: controlling the movement of the corresponding motor of the driving mechanism through the signal generated by the Hall rocker after processing, and finally completing the control of the movement of the cell probe. The sampling arm of the present invention has higher precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of cell probes, and particularly relates to a structure and method for controlling the movement of a micro-manipulation cell probe. Background Art

[0002] At present, due to the rapid development of the field of biochemistry, micro-manipulation has become an indispensable part of biological experiments. A variety of micro-manipulation devices have emerged on the market, but they are all separate microscope operating arms, and mostly adopt the structure of a stepper motor plus a lead screw. After sampling under the microscope, the sampling needle needs to be manually removed and fixed on the mass spectrometer. There is a lack of a micro-manipulation arm adapted for combined use with the mass spectrometer. During the manual operation, the shaking of the hand may cause the cells to detach from the probe, and it is easy to introduce dust or other substances in the environment.

[0003] In order to realize the combined use of the micro-manipulation arm and the mass spectrometer, it is first necessary to ensure that both can operate normally. Under the microscope, at least a three-axis robotic arm is required to control sampling, and under the mass spectrometer, at least a robotic arm with two degrees of freedom in the direction perpendicular to the mass spectrometry port is required. For two horizontally placed machines, these five degrees of freedom cannot be integrated with each other, so at least a five-degree-of-freedom robotic arm is required. At the same time, because the sampling arm is used for cell sampling, the repeat positioning accuracy needs to be high enough.

[0004] Existing micro-manipulation devices are all separate microscope operating arms. After sampling under the microscope, the sampling needle needs to be manually removed and fixed on the mass spectrometer. During the manual operation, the shaking of the hand may cause the cells to detach from the probe, and it is easy to introduce dust or other substances in the environment. And mostly adopt the structure of a stepper motor plus a lead screw, and it is impossible to avoid the backlash problem brought by the gear structure, resulting in a decrease in the accuracy of the sampling arm. Therefore, the present invention provides a structure and method for controlling the movement of a micro-manipulation cell probe. Summary of the Invention

[0005] The purpose of the present invention is to provide a structure and method for controlling the movement of a micro-manipulation cell probe. The present invention is a five-degree-of-freedom robotic arm, with the X, Y, and Z axes in an orthogonal relationship, and the R drive axis and the T drive axis are the other two axes added to the end of the first three-axis robotic arm. Since the first three orthogonal axes are relatively easy to achieve, the R drive axis and the T drive axis installed at the end of the first three axes are mainly discussed. In order to achieve high-precision and backlash-free motion control, here an innovative wire drive scheme is adopted to transfer the torque of the direct drive servo motor to the moving axis, realizing a 38-fold reduction under zero backlash, and improving the accuracy of the servo motor by 38 times, reaching a repeat positioning accuracy of 500 nm at the end.

[0006] The technical solution adopted by the present invention is specifically as follows:

[0007] A structure for controlling the movement of a microscopic operation cell probe, comprising a driving mechanism arranged at the output end of a three-axis robotic arm. The driving mechanism includes an R driving shaft and a T driving shaft. The cell probe is installed at the output end of the T driving shaft. The three-axis robotic arm and the driving mechanism are both electrically connected to a host computer. The host computer controls the movement of the cell probe by controlling the three-axis robotic arm and the driving mechanism.

[0008] A method for controlling the movement of a microscopic operation cell probe, the movement control method comprising the following steps:

[0009] Step 1: Power on and return to zero;

[0010] Mark the absolute positions of the motors of the three-axis robotic arm and the driving mechanism at this time as the zero point;

[0011] Step 2: Host computer control;

[0012] Complete the control of the movement of the motors of the three-axis robotic arm and the driving mechanism through the host computer to complete the control of the movement of the cell probe;

[0013] Step 3: Handle control;

[0014] Through the signals generated by the Hall rocker, after processing, control the movement of the motors corresponding to the R driving shaft and the T driving shaft, and finally complete the control of the movement of the cell probe.

[0015] Preferably, the specific steps of Step 1 are as follows: Each time power is on, to ensure that the probe does not interfere with the microscope and the mass spectrometer, the R driving shaft and the T driving shaft enter the zero return state. When the limit switch of the zero point is triggered by the mechanism, the zero return is completed, and the absolute positions of the motors of the three-axis robotic arm, the R driving shaft, and the T driving shaft at this time are marked as the zero point.

[0016] Preferably, the specific steps in Step 2 are as follows: When the cell probe is sampling and mass spectrometry scanning, the host computer sends position information through the serial port. The protocol is a custom 18-byte data, where the first 16 bytes of data are valid data and the last two are CRC fields. After the lower computer receives the data, it first performs CRC16 verification. After the verification passes, it then judges the limit information. If the current is in the limit state, the data of the sampling arm away from the zero point direction will be sent to the motor, and the data close to the zero point will be discarded. At the same time, the error flag bit is configured to reach the limit state; if it is not in the limit state, it directly controls the movement of the motors of the three-axis robotic arm, the R driving shaft, and the T driving shaft.

[0017] Preferably, in the second step, when the cell probe samples, a very stable end is required at this time. Therefore, innovatively, the R drive shaft and the T drive shaft enter the locking mode. In the locking mode, the servo motors of the R drive shaft and the T drive shaft work in the torque mode, and the motors will press the R drive shaft and the T drive shaft against zero with corresponding torques, avoiding the influence of the free shaft on the end of the sampling needle. Moreover, this solution does not require a separate mechanical structure, simplifies the mechanical structure and reduces costs.

[0018] When the cell probe performs mass spectrometry scanning, the requirement for end jitter is not so high at this time, and the motors of the three-axis robotic arm, R drive shaft, and T drive shaft can be controlled in a conventional manner.

[0019] Preferably, the third step includes the following specific steps: In the handle control mode, the single-chip microcomputer ADC collects the voltage of the Hall rocker. The ADC raw data range is 0 - 4096, and it is 2048 when there is no operation. The range of 2028 - 2068 is defined as the no-operation interval.

[0020] To prevent accidental error signals from causing end jitter, the data collected by the ADC needs to be processed. First, the data credibility is judged, that is, if the data is not in the no-operation interval for more than 10 consecutive times, the data is considered valid, and then low-pass filtering is performed to smooth the waveform. The processed data is not directly applied to the motor. Limit judgment is also made. Only when the current R drive shaft and T drive shaft are not at the zero position will the data be transmitted to the corresponding servo motor to control the corresponding servo motion.

[0021] The technical effects achieved by the present invention are:

[0022] The present invention is a five-degree-of-freedom robotic arm. The X, Y, and Z axes are in an orthogonal relationship. The R drive shaft and the T drive shaft are the other two axes added to the end of the first three-axis robotic arm. Since the first three orthogonal axes are relatively easy to implement, the R drive shaft and the T drive shaft installed at the end of the first three axes are mainly discussed. To achieve high-precision and backlash-free motion control, an innovative wire drive solution is adopted here to transmit the torque of the direct drive servo motor to the moving axis, achieving a 38-fold reduction under zero backlash and improving the accuracy of the servo motor by 38 times, reaching a repeat positioning accuracy of 500 nm at the end.

[0023] In the present invention, the wire drive reduction structure is used on a high-precision micromanipulation arm; the micromanipulation arm is controlled by a host computer using a custom protocol; the locking mode presses the R drive shaft and the T drive shaft against zero, ensuring that the R drive shaft and the T drive shaft are not affected by environmental vibrations and enhancing the anti-interference ability of the sampling arm.

[0024] In the present invention, applying a wire drive reduction structure to the sampling arm can achieve high precision at very low cost and with zero backlash; the locking mode makes the sampling arm insensitive to environmental vibrations, making the end more stable under the microscope; the whole machine does not require complex algorithms and can operate on a very low-cost MCU. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the front view of the driving mechanism in the structure of the movement control of a microscopic operation cell probe according to the present invention;

[0026] Figure 2 is the top view of the driving mechanism in the structure of the movement control of a microscopic operation cell probe according to the present invention;

[0027] Figure 3 is the overall view of the driving mechanism in the structure of the movement control of a microscopic operation cell probe according to the present invention;

[0028] Figure 4 is the general flowchart of a method for the movement control of a microscopic operation cell probe according to the present invention.

[0029] In the drawings, the list of components represented by each reference numeral is as follows:

[0030] 1. Driving mechanism; 11. R driving shaft; 12. T driving shaft. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the purpose and advantages of the present invention clearer, the present invention will be specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention, and does not strictly limit the scope of protection specifically claimed by the present invention.

[0032] As Figures 1-4 shown, a structure for the movement control of a microscopic operation cell probe includes a driving mechanism 1 provided at the output end of a three-axis robotic arm. The driving mechanism 1 includes an R driving shaft 11 and a T driving shaft 12. The cell probe is installed at the output end of the T driving shaft 12. The three-axis robotic arm and the driving mechanism 1 are both electrically connected to a host computer. The host computer controls the movement of the cell probe by controlling the three-axis robotic arm and the driving mechanism 1.

[0033] The present invention is a five-degree-of-freedom robotic arm. The X, Y, and Z axes are in an orthogonal relationship. The R driving shaft and the T driving shaft are the other two axes added to the end of the first three-axis robotic arm. Since the first three orthogonal axes are relatively easy to implement, the R driving shaft and the T driving shaft installed at the end of the first three axes are mainly discussed. The positional relationship between these two axes is as follows Figures 1-3As shown in the figure. To achieve high-precision and backlash-free motion control, an innovative wire drive solution is adopted here to transfer the torque of the direct drive servo motor to the motion axis, achieving a 38-fold reduction under zero backlash, improving the accuracy of the servo motor by 38 times, and reaching a repeat positioning accuracy of 500 nm at the end.

[0034] As Figures 1-4 shown, a motion control method for a micromanipulation cell probe, the motion control method includes the following steps:

[0035] Step 1: Power on and return to zero;

[0036] Mark the absolute positions of the motors of the three-axis robotic arm and the drive mechanism 1 at this time as the zero point;

[0037] The specific steps of Step 1 are as follows: Each time power is turned on, to ensure that the probe does not interfere with the microscope and the mass spectrometer, the R drive shaft 11 and the T drive shaft 12 enter the zero return state. When the zero limit switch of the mechanism is triggered, the zero return is completed, and the absolute positions of the motors of the three-axis robotic arm, the R drive shaft 11, and the T drive shaft 12 are marked as the zero point.

[0038] Step 2: Host computer control;

[0039] Complete the control of the motors of the three-axis robotic arm and the drive mechanism 1 through the host computer to complete the motion control of the cell probe;

[0040] The specific steps in Step 2 are as follows: When the cell probe is sampling and performing mass spectrometry scanning, the host computer sends position information through the serial port. The protocol is a custom 18-byte data, where the first 16 bytes of data are valid data, and the last two are CRC fields. After the lower computer receives the data, it performs CRC16 verification first. After the verification passes, it then judges the limit information. If it is currently in the limit state, the data that makes the sampling arm move away from the zero point direction will be sent to the motor, and the data close to the zero point will be discarded. At the same time, the error flag bit is configured to reach the limit state; if it is not in the limit state, it directly controls the motors of the three-axis robotic arm, the R drive shaft 11, and the T drive shaft 12 to move.

[0041] When the cell probe is sampling, a very stable end is required at this time. Therefore, the innovative R drive shaft 11 and T drive shaft 12 enter the locking mode. In the locking mode, the servo motors of the R drive shaft 11 and T drive shaft 12 work in the torque mode, and the motors will press the R drive shaft 11 and T drive shaft 12 against the zero point with the corresponding torque, avoiding the influence of the free shaft on the end of the sampling needle. And this solution does not require a separate mechanical structure, simplifies the mechanical structure and reduces costs;

[0042] When the cell probe performs mass spectrometry scanning, the requirement for end jitter is not so high at this time, and the motors of the three-axis robotic arm, R drive shaft 11, and T drive shaft 12 can be controlled in a conventional manner.

[0043] Step 3: Handle control;

[0044] The signals generated by the Hall rocker are processed to control the corresponding motor movements of the R drive shaft 11 and the T drive shaft 12, and finally the movement control of the cell probe is completed.

[0045] Step 3 specifically includes the following steps: In the handle control mode, the single-chip microcomputer ADC collects the voltage of the Hall rocker. The original ADC data range is 0 - 4096, and it is 2048 when there is no operation. The range of 2028 - 2068 is defined as the no-operation interval;

[0046] To prevent accidental error signals from causing end jitter, the data collected by the ADC needs to be processed. First, judge the data credibility, that is, if the data is not in the no-operation interval for more than 10 consecutive times, the data is considered valid, and then low-pass filtering is performed to smooth the waveform; the processed data is not directly applied to the motor. A limit judgment is also made. Only when the current R drive shaft 11 and T drive shaft 12 are not in the zero position will the data be transmitted to the corresponding servo motor to control the corresponding servo movement.

[0047] In the present invention, the wire drive reduction structure is used on the high-precision micromanipulation arm; the micromanipulation arm is controlled by the host computer using a custom protocol; the locking mode presses the R drive shaft 11 and the T drive shaft 12 at the zero point to ensure that the R drive shaft 11 and the T drive shaft 12 are not affected by environmental vibrations and enhance the anti-interference ability of the sampling arm.

[0048] In the present invention, using the wire drive reduction structure on the sampling arm can achieve very high precision and zero backlash at a very low cost; the locking mode makes the sampling arm insensitive to environmental vibrations and makes the end more stable under the microscope; the whole machine does not require complex algorithms and can run on a very low-cost MCU.

[0049] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. The structures, devices, and operation methods not specifically described and explained in the present invention are implemented according to the conventional means in the art without special description and limitation.

Claims

1. A method for controlling the movement of a microscopic operation cell probe, characterized in that: The described motion control method is the motion control method for the structure of the cell probe motion control in micromanipulation. The structure of the cell probe motion control in micromanipulation includes a driving mechanism (1) arranged at the output end of a three-axis robotic arm. The driving mechanism (1) includes an R driving shaft (11) and a T driving shaft (12). The cell probe is installed at the output end of the T driving shaft (12). Both the three-axis robotic arm and the driving mechanism (1) are electrically connected to a host computer. The host computer completes the motion control of the cell probe by controlling the three-axis robotic arm and the driving mechanism (1). The motion control method includes the following steps: Step 1: Power on and return to zero; Mark the absolute positions of the motors of the three-axis robotic arm and the driving mechanism (1) at this time as the zero point; Step 2: Host computer control; The host computer controls the motors of the three-axis robotic arm and the driving mechanism (1) to complete the motion control of the cell probe; Step 3: Handle control; The signals generated by the Hall rocker are processed to control the motors corresponding to the R driving shaft (11) and the T driving shaft (12), and finally the motion control of the cell probe is completed.

2. The method for controlling the movement of a microscopic operation cell probe according to claim 1, characterized in that: The specific steps of Step 1 are as follows: Each time power is turned on, the R driving shaft (11) and the T driving shaft (12) enter the zero return state. When the limit switch at the zero point is triggered by the mechanism, the zero return is completed, and the absolute positions of the motors of the three-axis robotic arm, the R driving shaft (11), and the T driving shaft (12) at this time are marked as the zero point.

3. A method for controlling the movement of a microscopic operation cell probe according to claim 1, characterized in that: The specific steps in Step 2 are as follows: When the cell probe is sampling and performing mass spectrometry scanning, the host computer sends position information through the serial port. The protocol is 18-byte data defined by itself, where the first 16 bytes of data are valid data and the last two bits are the CRC field. After the lower computer receives the data, it first performs CRC16 verification. After the verification passes, it then judges the limit information. If it is currently in the limit state, the data of the sampling arm moving away from the zero point direction will be sent to the motor, and the data close to the zero point will be discarded. At the same time, the error flag bit is configured to the limit state; if it is not in the limit state, it directly controls the motors of the three-axis robotic arm, the R driving shaft (11), and the T driving shaft (12).

4. A method for controlling the movement of a microscopic operation cell probe according to claim 3, characterized in that: In Step 2, when the cell probe is sampling, the R driving shaft (11) and the T driving shaft (12) enter the locking mode. In the locking mode, the servo motors of the R driving shaft (11) and the T driving shaft (12) work in the torque mode, and the motors will press the R driving shaft (11) and the T driving shaft (12) against the zero point with the corresponding torque; When the cell probe is performing mass spectrometry scanning, the motors of the three-axis robotic arm, the R driving shaft (11), and the T driving shaft (12) are controlled in the conventional manner.

5. The method for controlling the movement of a microscopic operation cell probe according to claim 1, wherein: Step 3 includes the following specific steps: In the handle control mode, the single-chip microcomputer ADC collects the voltage of the Hall rocker. The original ADC data range is 0 - 4096, and it is 2048 when there is no operation. The range of 2028 - 2068 is defined as the no-operation interval; Process the data collected by the ADC. First, judge the data credibility. That is, if the data continuously exceeds the no-operation range for more than 10 times, the data is considered valid. Then, perform low-pass filtering to smooth the waveform. After processing, the data is judged for limit. Only when the current R drive shaft (11) and T drive shaft (12) are not in the zero position, the data will be transmitted to the corresponding servo motor to control the corresponding servo motion.

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